WIP: Smyth grammar reader

Continuation of #189 

Enables a user to click on a Smyth category and pull in the grammatical definition right into the plugin.

A quick and dirty solution - might solve this differently in the future (especiialy for potential reuse).

It's also quite slow, as the jQuery selectors we run are not blazing fast - not because jQuery is slow, but because the selection logic is stupid...

This PR is opened to help to keep track of the work that still needs to be done before we are finished here:

- [ ] Smyth HTML styling - uses tei CSS classes
- [ ] Links to other sections - might have to patch up the original HTML files here
- [ ] Fix possible duplication of sections: If section 1 contains section 2, and the requested sections are 1 & 2, 2 will be duplicated: As part of 1 and as stand-alone element.