Since plugins are configured in a separate file, the README now tells
people to put commands in plugins.json instead of options.json.

There's no more pass_words option, so we shouldn't mention that anymore.
Also, commands aren't in a configuration section called "commands"
anymore, so use the new name, ".shell".

It actually does do the things claimed in the first sentence, so don't
use the future tense.

There's no need to tell the user the details of intermediate steps in
generating the language.  All the user needs to know is that it uses the
network to update the language model when it starts.

More Python-friendly, yada yada yada.