1. I was the first person to use a .rs domain for Rust stuff. I wrote a bit about doing so in https://chrismorgan.info/blog/introducing-teepee/ (heading “Aside: registering .rs domains”). I never finished Teepee, and allowed teepee.rs to lapse (and it hadn’t actually been being used yet, anyway; I would also note that this was from before a lot of the infrastructure we take for granted today existed, including docs.rs).

2. Not every single library has its docs built automatically by docs.rs. For starters, not all crates are on crates.io: some deliberately stick with Git dependencies. But even of things on crates.io, docs.rs will fail to build some, normally due to packager error or some failed FFI linkage (for which the most common solution is to vendor a copy of the foreign library code, either opt-out or opt-in with an instruction for docs.rs to opt in), but it’s possible to deliberately thwart just the building of docs (or even just docs.rs) if you really want to, for which I present another of my transgressions: https://docs.rs/crate/u-plus/latest (source of the prevention: https://git.chrismorgan.info/u-plus/blob/HEAD:/src/lib.rs, lines 4–5).