Cleaned up formatting and re-worked instructions append.

Author: BethanyG

exercises/practice/error-handling/.docs/instructions.append.md

@@ -1,8 +1,11 @@
-# Hints
+# Instructions append
+
+## Some hints
 
 For the `filelike_objects_are_closed_on_exception` function, the `filelike_object`
-will be an instance of a custom `FileLike` class defined in the test suite. This
-class implements the following methods:
+will be an instance of a custom `FileLike` class defined in the test suite.
+This class implements the following methods:
+
 - `open` and `close`, for explicit opening and closing.
 - `__enter__` and `__exit__`, for implicit opening and closing.
 - `do_something`, which may or may not throw an `Exception`.

exercises/practice/high-scores/.docs/instructions.append.md

@@ -1,7 +1,10 @@
 # Instructions append
 
-In this exercise, you're going to use and manipulate lists. Python lists are very versatile, and you'll find yourself using them again and again in problems both simple and complex.
+In this exercise, you're going to use and manipulate [`lists`][lists].
+Python lists are very versatile, and you'll find yourself using them again and again in problems both simple and complex.
 
 - [**Data Structures (Python 3 Documentation Tutorial)**](https://docs.python.org/3/tutorial/datastructures.html)
 - [**Lists and Tuples in Python (Real Python)**](https://realpython.com/python-lists-tuples/)
 - [**Python Lists (Google for Education)**](https://developers.google.com/edu/python/lists)
+
+[lists]: https://docs.python.org/3/library/stdtypes.html#lists