introduce json schema checking with
https://github.com/geraintluff/jsv4-php
enhanced error checking workflow, both server and client side
- json schema checking server side
- refactor word.id to word.ID to bypass https://github.com/geraintluff/jsv4-php/issues/9
- string sanitation both server and client side
create table on plugin activation,
table now has (project, name) as primary key
yet missing: error processing for `project`
Fix: load default only if no name is specified,
draw markings for pre-existing words if a name is specified in build mode