* Add links to the sidebar.
* Remove unnecessary `page-ref`s (these links are now in the sidebar).
* Small grammar/style fix.
* Fix code tabs.
* Remove {% page-ref %} uses.
* Fix some line lengths.
* Split out `custom.css` into multiple files.
* Remove duplicate titles.
* Update optimizations.md:
* Make some sentences more clear
* Add additional links and references ("further reading")
* Capitalise some proper nouns
* Add missing terms to the dictionary.
* Split out a paragraph.
* Fix spelling.
* Update links.
* Apply suggestions from code review
Co-authored-by: Simon <simon@siku2.io>
* Update docs/advanced-topics/optimizations.md
Co-authored-by: Simon <simon@siku2.io>