Format all instructions.append.md to start with an H1 (required but ignored) and H2 (#2844)

Author: IsaacG

exercises/practice/anagram/.docs/instructions.append.md

@@ -1,3 +1,5 @@
 # Instructions Append
 
+## Implementation
+
 The anagrams can be returned in any order.

exercises/practice/armstrong-numbers/.docs/instructions.append.md

@@ -1,3 +1,7 @@
+# Instructions append
+
+## Implementation
+
 <!-- prettier-ignore-start -->
 ~~~~exercism/note
 Some of the tests might pass a `BigInt` as input.

exercises/practice/book-store/.docs/instructions.append.md

@@ -1,4 +1,6 @@
-# Implementation
+# Instructions append
+
+## Implementation
 
 Define a function - `cost` - that calculates the cost for a given list of books based on defined discounts.
 

exercises/practice/clock/.docs/instructions.append.md

@@ -1,3 +1,5 @@
 # Instructions append
 
+## Implementation
+
 Using the built-in [Date class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) and its methods is not allowed.

exercises/practice/collatz-conjecture/.docs/instructions.append.md

@@ -1,5 +1,7 @@
 # Instructions append
 
+## Implementation
+
 If `n` is not a positive integer, stop the program from being executed further and return an error message.
 
 In JavaScript, this can be done using the `throw` statement.

exercises/practice/linked-list/.docs/instructions.append.md

@@ -1,5 +1,7 @@
 # Instructions append
 
+## Implementation
+
 Your list must also implement the following interface:
 
 - `delete` (delete the first occurrence of a specified value)

exercises/practice/list-ops/.docs/instructions.append.md

@@ -1,3 +1,5 @@
 # Instructions append
 
+## Implementation
+
 Using core language features to build and deconstruct arrays via destructuring, and using the array literal `[]` are allowed, but no functions from the `Array.prototype` should be used.

exercises/practice/meetup/.docs/instructions.append.md

@@ -1,5 +1,7 @@
 # Instructions append
 
+## Implementation
+
 In JavaScript, the Date object month's index ranges from 0 to 11.
 
 ```javascript

exercises/practice/nucleotide-count/.docs/instructions.append.md

@@ -1,5 +1,7 @@
 # Instructions append
 
+## Implementation
+
 The result should be formatted as a string containing 4 numbers separated by spaces.
 Each number represents the count for A, C, G and T in this order.
 

exercises/practice/protein-translation/.docs/instructions.append.md

@@ -1,5 +1,7 @@
 # Instructions append
 
+## Implementation
+
 If an invalid character or codon is encountered _during_ translation, it should `throw` an error with the message `Invalid codon`.
 
 ```javascript