[DO NOT MERGE] convert to outline-apps repository, approach #1: single workspace

[daniellacosse]

This is proving to be about as annoying as I expected... with this approach, I'm trying to stick to only having one root NPM workspace. See Approach #2 for an alternative.

Tradeoffs:

• Pro: One single NPM Workspace that's compatible with all the open source best practices and tooling we currently have out there
• Pro: Less space on disk as all node dependencies will be deduped down into a single node_modules (or .yarn)
• Pro: infrastructure can be very elegantly shared via things like

import { copyDir } from "@infrastructure/file";

• Con: Lots of changes needed and realistically we'll probably need to do this in several medium-large chunks rather than massively all at once.
• Con: Can only use one workspace toolchain and version of node at a time (can't use both npm workspaces and yarn workspaces)
• Is there anything I'm not thinking of?

Current Issues:

• do we need a root third_party folder?
• do we need a root docs folder to preserve the invitation-instructions.md link?

[fortuna]

It looks like you need to delete the built stuff here