Update and reformat all READMEs (exercism#950)

* Move 'Submitting Exercises' to heading level 2

* Regenerate READMEs using configlet

* diffie-hellman: add hints.md and regenerate README

* collatz-conjecture: add hints.md and regenerate README

* simple-cipher: suggest returning a ValueError

* two-fer: Remove Test-Driven Development section

Author: Nathan Parsons

docs/EXERCISE_README_INSERT.md

@@ -1,9 +1,8 @@
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).

exercises/accumulate/README.md

@@ -25,16 +25,12 @@ Keep your hands off that collect/map/fmap/whatchamacallit functionality
 provided by your standard library!
 Solve this one yourself using other basic tools instead.
 
-Lisp specific: it's perfectly fine to use `MAPCAR` or the equivalent,
-as this is idiomatic Lisp, not a library function.
-
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/acronym/README.md

@@ -7,14 +7,12 @@ Techies love their TLA (Three Letter Acronyms)!
 Help generate some jargon by writing a program that converts a long name
 like Portable Network Graphics to its acronym (PNG).
 
-
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/all-your-base/README.md

@@ -6,6 +6,7 @@ Implement general base conversion. Given a number in base **a**,
 represented as a sequence of digits, convert it to base **b**.
 
 ## Note
+
 - Try to implement the conversion yourself.
   Do not use something else to perform the conversion for you.
 
@@ -28,16 +29,14 @@ The number 1120, *in base 3*, means:
 
 I think you got the idea!
 
-
 *Yes. Those three numbers above are exactly the same. Congratulations!*
 
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/allergies/README.md

@@ -29,14 +29,12 @@ allergens that score 256, 512, 1024, etc.).  Your program should
 ignore those components of the score.  For example, if the allergy
 score is 257, your program should only report the eggs (1) allergy.
 
-
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/alphametics/README.md

@@ -7,7 +7,7 @@ letters in words are replaced with numbers.
 
 For example `SEND + MORE = MONEY`:
 
-```
+```text
   S E N D
   M O R E +
 -----------
@@ -16,7 +16,7 @@ M O N E Y
 
 Replacing these with valid numbers gives:
 
-```
+```text
   9 5 6 7
   1 0 8 5 +
 -----------
@@ -31,13 +31,12 @@ a multi-digit number must not be zero.
 
 Write a function to solve alphametics puzzles.
 
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/anagram/README.md

@@ -6,13 +6,12 @@ Given `"listen"` and a list of candidates like `"enlists" "google"
 "inlets" "banana"` the program should return a list containing
 `"inlets"`.
 
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/atbash-cipher/README.md

@@ -9,7 +9,7 @@ letter, the second with the second-last, and so on.
 
 An Atbash cipher for the Latin alphabet would be as follows:
 
-```plain
+```text
 Plain:  abcdefghijklmnopqrstuvwxyz
 Cipher: zyxwvutsrqponmlkjihgfedcba
 ```
@@ -23,17 +23,17 @@ being 5 letters, and punctuation is excluded. This is to make it harder to guess
 things based on word boundaries.
 
 ## Examples
+
 - Encoding `test` gives `gvhg`
 - Decoding `gvhg` gives `test`
 - Decoding `gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt` gives `thequickbrownfoxjumpsoverthelazydog`
 
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/beer-song/README.md

@@ -4,7 +4,7 @@ Produce the lyrics to that beloved classic, that field-trip favorite: 99 Bottles
 
 Note that not all verses are identical.
 
-```plain
+```text
 99 bottles of beer on the wall, 99 bottles of beer.
 Take one down and pass it around, 98 bottles of beer on the wall.
 
@@ -320,13 +320,12 @@ are some additional things you could try:
 Then please share your thoughts in a comment on the submission. Did this
 experiment make the code better? Worse? Did you learn anything from it?
 
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).
 

exercises/binary-search/README.md

@@ -34,13 +34,12 @@ A binary search halves the number of items to check with each iteration,
 so locating an item (or determining its absence) takes logarithmic time.
 A binary search is a dichotomic divide and conquer search algorithm.
 
-### Submitting Exercises
+## Submitting Exercises
 
 Note that, when trying to submit an exercise, make sure the solution is in the `exercism/python/<exerciseName>` directory.
 
 For example, if you're submitting `bob.py` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/python/bob/bob.py`.
 
-
 For more detailed information about running tests, code style and linting,
 please see the [help page](http://exercism.io/languages/python).