Fixes more edge cases that can happen when typing incomplete/partial markup into the slot input.

Fixes edgecases that can occur while typing in real time into a slot input for a component being demo'd. Filters out invalid characters from possible attribute names.

* Added a missing style token the main list of all tokens. * Renamed `doxenPlainText` style token to `plainText` to match the naming convention.

Fixes an edge case where invalid HTML attribute names are generated while typing into the slot input, causing a console error.

* Fixed issues with the new slot system * Weird nesting issue fixed * Missing text nodes fixed * Missing attributes on root element fixed * Unit tests in place for slot rendering

After much trial and error, I've come up with a solution to how to handle props. * It does not wrap the content in an extra element * Supports multiple root-level elements * Updates as you type * Does not throw errors for invalid markup * Has no cross-contamination between slots when a component being demo'd uses multiple slots

**Features:** * Skips inner accordion keyboard navigation and screen reading when closed. **Maintenance:** * Updated dependencies **Diff:** * https://github.com/TheJaredWilcurt/vue-doxen/compare/v07.3..v0.7.4

**Features:** * Simplified the accordion component, now only goes up, no longer goes left. Moved docs outside of it to demo file. **Maintenance:** * Renamed `app` folder to `docs` to be more clear. **Diff:** * https://github.com/TheJaredWilcurt/vue-doxen/compare/v07.2..v0.7.3