Call for action: Easily improve D's ecosystem - DUB documentation improvements

[WebFreak001]

Additional things that are quite low priority, but might be 
interesting for anyone who is looking to contribute on the tech 
side:

- auto-testing what's written in the docs is probably a good 
idea. Ideally by extracting the markdown, but not required. 
Should test whole dub packages
- D source code could be validated for syntax and output (e.g. 
using https://code.dlang.org/packages/md)
- auto-deployment is still missing, GitHub pages and actions 
could be used with this (especially interesting for PRs)
- dead link detection is probably gonna be useful soon 
(awesome-dlang has a GitHub actions workflow for this, could 
reuse that)
- "Run in online IDE" button for code using run.dlang.io would be 
useful - can use single file packages there.