[Pre-RFC] DNS domains as package namespaces

I think it would be premature to write up the "alternatives considered" section of the RFC before knowing whether the Cargo and crates.io teams are OK with the concept of namespaces. After all, the entire thread would just end if someone from one of those teams posts "no we still don't want namespaces, ask again in five years". The bullet points in the first post are faster to read than lengthy prose, and certainly faster to write. If the relevant teams are interested in proceeding to a full RFC then don't worry, you'll have plenty of reading material. My Obsidian tag on this topic (collecting known namespacing designs + considering their applicability to Rust) runs to several tens of thousands of lines.