Fix HTML detection, ref #164 (thanks @astynax).
Security
Add an initial Security.md file.
Add extra sanitation / XXS protection (thanks @Bnyt7).
New features
Add support for serving the QOI image format.
Code quality
Simplify favicon / mimetype related code.
Remove some unused code.
Documentation
Add more documentation, ref #163 (thanks @myselfghost).
Add an example for HTMX.
Performance
Build release executables with GOEXPERIMENT=greenteagc.
Lua related
If a single file is given as an argument, don't output the server name and version (to make Algernon more suitable for being used as a "Lua runtime", ref #163).
General
