Lychee is a [Rust based](https://lychee.cli.rs) async parallel link
checker.
I ran it against the codebase to suss out stale links and fixed those
up.
There's currently 2 remaining cases that I don't know how to resolve:
1. https://flathub.org/apps/dev.zed.Zed - nginx is giving a 502 bad
gateway
2.
https://github.com/zed-industries/zed/actions/workflows/ci.yml/badge.svg
- I don't want to mess with the CI pipeline in this PR.
Once again, I'll punt to the Docs Czar to see if this gets incorporated
into CI later.
---
## Running `lychee` locally:
```
cargo binstall -y lychee
lychee .
```
---
Release Notes:
- N/A
Signed-off-by: mrg <miguelraz@ciencias.unam.mx>