CHORE: prep for v0.4.0

[billchurch]

Notes while I'm building out v0.4.0

rough plans:

• upgrade socket.io to 4.1.x
• code linting, readability improvements
• go through and eliminate any orphaned modules in dev deps
• target node 14
• adopt airbnb javascript style (semicolons, gross but the cool kids are doing it)
• migrate client js to typescript
• ???
• profit