Also improve and expand the tests abit. Use serde_json to parse the
results an interpret them instead on depending on response body string
matching (which fails for changing mtimes of the test files).
* The root location now shows all lists
* The specific list locations show only the specified list
* Each list can be individually edited
* Use the card columns (masonry) layout when showing all lists
* No longer support HTML previewing, just switch between editing
and viewing (ala Github comments)
* Manage the vector of loads lists in the state
* Use a struct as the context for the index template
* Rework the _layout and index templates; remove hardcoded examples