Inclusion of docs into /public slows down dev environment immensely

[thilobillerbeck]

Due to the size of the docs and the nature of the astro dev server keeping track of all the files it serves the dev environment is cluttered and slow. This should be split up. This has been brought up once again in #1627

Proposal

• Dev Environment: Serve the docs from a different program (Python HTTP Server, etc.) and use Vites proxy functionality to include it into the astro dev environment.
• Build: Either configure Vite to copy the manuals over or include them into dist after the build is done