feat: add forumTopicId to challenge frontmatter [pre-existing]

This commit adds the pre-existing challenge guide topics in the
forum to the forntmatter of their challenge markdown files.

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/combine-an-array-into-a-string-using-the-join-method.english.md

@@ -2,6 +2,7 @@
 id: 587d7daa367417b2b2512b6c
 title: Combine an Array into a String Using the join Method
 challengeType: 1
+forumTopicId: 18221
 ---
 
 ## Description

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/sort-an-array-alphabetically-using-the-sort-method.english.md

@@ -2,6 +2,7 @@
 id: 587d7da9367417b2b2512b69
 title: Sort an Array Alphabetically using the sort Method
 challengeType: 1
+forumTopicId: 18303
 ---
 
 ## Description

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/split-a-string-into-an-array-using-the-split-method.english.md

@@ -2,6 +2,7 @@
 id: 587d7daa367417b2b2512b6b
 title: Split a String into an Array Using the split Method
 challengeType: 1
+forumTopicId: 18305
 ---
 
 ## Description

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/use-the-filter-method-to-extract-data-from-an-array.english.md

@@ -2,6 +2,7 @@
 id: 587d7b8f367417b2b2512b63
 title: Use the filter Method to Extract Data from an Array
 challengeType: 1
+forumTopicId: 18179
 ---
 
 ## Description

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/use-the-map-method-to-extract-data-from-an-array.english.md

@@ -2,6 +2,7 @@
 id: 587d7b8f367417b2b2512b61
 title: Use the map Method to Extract Data from an Array
 challengeType: 1
+forumTopicId: 18214
 ---
 
 ## Description