Add automatic `emit`ting of events to trigger

All bubbling events (events ending in `"inside"`) had a ``normal''
counterpart. This addition changes that, and automatically calls
`emit` inside `trigger`.

- Previously `trigger` accepted ``inside'' events, now, `trigger`
  accepts normal events and adds the ``inside'' part when
  triggering on parents (and their constructor) starts;
- Previously `trigger` received `name`, and `values...`, now,
  `trigger` accepts `name`, `context`, and `values...`.
Refactor in Readme.md

This includes a complete overhaul, links to NLCST,
better examples, and and update for 54de11f.

- Complete rewrite;
- Add NLCST links instead of custom semantics
  descriptions;
- Remove examples for `type`s;
- Add documentation for `nodeName`s;
- Add documentation for `Element#split()`;
- Add documentation for `Node#valueOf()` and
  `Text#valueOf()`;
- Fix bug in IDL where `WordNode` and `WhiteSpaceNode`
  were incorrectly classified as `Parent` (instead of
  the correct `Element`);
- Update documentation for 54de11f: Automatic
  `emit`ting of events for `trigger`.