Change menu to be context menu

No sense having context-free command for doc singe it always pertains to
a workspace location
Change keymap modifier to ctrl-alt

It seems shift doesn't work, it just types a delta character.
Implement launching repl and talking to it

For some reason I can't use Bufferedprocess to do this, piped stdin
doesn't seem to work.
Run repl in project dir
Show docs in split view

View stuff heavily inspired by https://github.com/rgbkrk/atom-python