Update contributing documentation broken link

Author: bahung1221

CONTRIBUTING.md

@@ -5,13 +5,12 @@ appreciated and encouraged.
 
 ## Table of contents
 
-1. [Code of Conduct](code-of-conduct)
-2. [How to contribute](how-to-contribute)
-    1. [Creating issues](creating-issues)
-    2. [Opening pull requests](opening-pull-requests)
-    3. [JS Docblocks](js-docblocks)
-4. [How to run locally](how-to-run-locally)
-3. [Additional information](additional-information)
+1. [Code of Conduct](#code-of-conduct)
+2. [How to contribute](#how-to-contribute)
+    1. [Creating issues](#creating-issues)
+    2. [Opening pull requests](#opening-pull-requests)
+    3. [JS Docblocks](#js-docblocks)
+4. [How to run locally](#how-to-run-locally)
 
 ## Code of Conduct