Outstanding documentation tasks and project tidy up.

[davetcc]

There's now considerable missing documentation around the new mode of operation:

• At a minimum document how the new initialiser mode works, IE take the project as a zip, work with it yourself, and only round trip when absolutely needed. Explain how putting the menu in the INO options prevents it being overwritten.
• Document how all-in-one mode works, and how it changes both plugins and i18n.
• Document how the round trip mode works within the browser
• Document the python script tcmenu-i18n.py for people who don't want to round trip