Update code-description.md

Author: hubwriter

code-description.md

@@ -13,23 +13,25 @@ The code is written in TypeScript. This file describes how the code works.
   - [Version nesting](#version-nesting)
 - [How the code works](#how-the-code-works)
   - [1. Parsing the Markdown file](#1-parsing-the-markdown-file)
-    - [Processing each version tag]()
-    - [Example]()
-    - [Results of parsing]()
+    - [Processing each version tag](#processing-each-version-tag)
+    - [Example](#example)
+    - [Results of parsing](#results-of-parsing)
   - [2. Highlighting tags and displaying a versioning message](#2-highlighting-tags-and-displaying-a-versioning-message)
-    - [Highlighting the relevant version tags]()
-    - [Removing the highlighting]()
-    - [Displaying a versioning message]()
+    - [Highlighting the relevant version tags](#highlighting-the-relevant-version-tags)
+    - [Removing the highlighting](#removing-the-highlighting)
+    - [Displaying a versioning message](#displaying-a-versioning-message)
 - [Reference](#reference)
   - [Variables and constants in alphabetical order](#variables-and-constants-in-alphabetical-order)
   - [Tag object properties](#tag-object-properties)
   - [Per-tag explanation](#per-tag-explanation)
-    - [All tags]()
-    - [``]()
-    - [``]()
-    - [``]()
-    - [``]()
+    - [All tags](#all-tags)
+    - [`ifversion`](#ifversion)
+    - [`elsif`](#elsif)
+    - [`else`](#else)
+    - [`endif`](#endif)
   - [Regular expression](#regular-expression)
+    - [The regular expression broken down](#the-regular-expression-broken-down)
+    - [Using the regular expression](#using-the-regular-expression)
   - [The package.json file](#the-packagejson-file)
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