Add GA updates to documentation, Close academicpages#265

Author: rjzupkoii

_pages/markdown.md

@@ -30,10 +30,14 @@ redirect_from:
   * Orange circle: building
   * Red X: error
   * No icon: not built
+
 * Academic Pages uses [Jekyll Kramdown](https://jekyllrb.com/docs/configuration/markdown/), GitHub Flavored Markdown (GFM) parser, which is similar to the version of Markdown used on GitHub, but may have some minor differences. 
   * Some of emoji supported on GitHub should be supposed via the [Jemoji](https://github.com/jekyll/jemoji) plugin :computer:.
   * The best list of the supported emoji can be found in the [Emojis for Jekyll via Jemoji](https://www.fabriziomusacchio.com/blog/2021-08-16-emojis_for_Jekyll/#computer) blog post.
 
+* While GitHub Pages prevents server side code from running, client-side scripts are supported.
+  * This means that Google Analytics is supported, and [the wiki](https://github.com/academicpages/academicpages.github.io/wiki/Adding-Google-Analytics) should contain the most up-to-date information on getting it working.
+
 ## Resources
  * [Liquid syntax guide](https://shopify.github.io/liquid/tags/control-flow/)
  * [MathJax Documentation](https://docs.mathjax.org/en/latest/)