Update and enhance README

[cyrusae]

• [x] Rewrite "run locally" section with more detail and link to bobadocs
• [x] Edit counterpart docs to match new tone
• [x] More detail in contributions section
• [ ] Add link to doc on contributions once relevant
• [ ] Add brief sentence elaborating on what "vaguely inspired by Tumblr's" means in practice in first paragraph
• [x] Add "install (at your own risk)" section
• [ ] Add more links to bobadoc updates as available
• [x] Decide what else to add
• [x] Get feedback/further drafting

Potential additions based on readme.so template options:

• [ ] Roadmap or link to one?
• [x] License section?
• [ ] readme.so suggests noting what command to use for running tests; could pull double duty as blurb under which to link doc on testing if we want that?
• [ ] A lot of these sections are cool but kind of docs territory (e.g. features, tech stack); probably better to take as a guide as far as what to provide direct links to on top of the overview once able.
• [ ] Add screenshots with/alongside demo y/n?
• [ ] Do we have more documentation on how to contribute
• [ ] (Do we have a code of conduct we want to stick there, for that matter, since it's suggested as standard)
• [x] Related (at the end, link to other bobarepos)

[cyrusae]

Current status

[cyrusae]

Put 'tell us what would make you not be hesitating to contribute right now' link lead to bobadocs issues because it seems like the most internally consistent place to keep issues that are intrinsically about documentation/long-term communications, in that that's the repo that doesn't have another intended end product people could psych themselves into believing their feedback was a "distraction" from. But also I should probably write out my logic for what issues seem reasonable to put where and make sure it's in line with everyone else's.

[cyrusae]

• [ ] Update this issue with what tasks are the size of this udpate and what will be ongoing
• [ ] Last couple edits
• [ ] Cyrus do the actual PR