* initial setup of component
* initial styles applied
* add some initial docs
* small tweaks to story
* add some very initial tests
* tweaks to styles to add border bottom
* add some preact tests
* import default style in jsx, ignore in jest
* WIP - create MentionAutocompleteListener, attempt to position popover
* position dropdown correctly, exit selection in various scenarios
* refactor
* make sure cursor placed correctly after selection
* only import autocomplete when needed
* rename files, add jsdoc
* update tests and story notes
* tidy up scss file
* fix story styling
* fix aria label in story
* fix issue with key event not triggering in mobile
* position dropdown at input left if small screen
* fix issue with deleting and re-entering
* don't trigger search if directly following a letter or number
* stop change event being fired with highihted text
* move regex out of function into constant
