V6 Docs

[MarshallOfSound]

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project follows, as appropriate.
• The changes are appropriately documented (if applicable).
• The changes have sufficient test coverage (if applicable).
• The testsuite passes successfully on my local machine (if applicable).

WIP site can be viewed at: https://v6.electronforge.io/

TODO:

• Landing
• Introduction (README)
• Configuration (just packager / rebuild configs and general tricks for setting config like env vars and such)
• CLI
• API Docs (auto-generated)
• Plugins (probably won't finish in this PR, the plugins aren't technically read yet)
• Makers
• Publishers
• Debugging (the stuff that used to be at the bottom of the readme)
• Extending Forge
• Add doc comments for the PublisherOptions interface
• Add doc comments for the MakerOptions interface

[MarshallOfSound]

I know the commits look super weird on this PR, but we'll just squash and merge and it'll all be fine 😆

[MarshallOfSound]

Current plan is to put a giant "THIS IS A WORK IN PROGRESS / BETA" banner on the top of the plugins docs page, just to give us time to play with / make work properly 😄

[MarshallOfSound]

Only thing pending is filling out the landing page of https://v6.electronforge.io/ with some info or something 🤔

Probably just general overview of forge / project goals / link to Getting Started. Can deal with that after this is merged