Started basic playground for testing lexical as a new WYSIWYG editor.
Moved out tinymce to be under wysiwyg-tinymce instead so lexical is the
default, but TinyMce code remains.
Updated reply inidicator to fit with new nesting system, only showing on
view when nest within nesting structure.
Updated the general design to be a bit cleaner and better adapt on
mobile.
Tested on FF+Chrome, inc. dark mode.
