Overhaul Specification [RFC]

[What42Pizza]

I'm not even sure if this new version is objectively better than what already exists, but I definitely prefer it. My main goal here was to remove details I see as unnecessary and add details that I think are necessary, though I've also majorly reworked everything else.

This definitely needs more thought than any other PR I've made, and I'd like to know what should be changed before this might be merged. One subtle change this new version makes is that the new specification isn't exactly based off how people use non-semver versioning, which was a big guiding principle with the initial version of romver. In terms of functionality, this mainly affects the definition of pre-release and build-metadata identifiers, and my proposed changes say that these identifiers only have to be any ascii string of alphanumerics, dots, and hyphens. Other than that, though, the functionality of the spec should be mostly the same. There's also a few miscellaneous changes to the readme.

Also, if this goes through then I'd also like to be an official maintainer of this repo, though I don't think there's much else I want to change, I mostly just want to have maintainer-level authority in future RFCs.