Categorization overhaul and data export

Changes Categories are now called Tags to better reflect their role in the app Features Adding feeds to views Feeds can be directly assigned to views This greatly reduces the friction in organizing feeds into categories, as there isn't a need for an intermediate tag App dialogs and feed management page updated to enable adding feeds to views Data export to .opml Added settings section to export feed data to .opml Can group feeds either by view or tag on export according to your needs/preferences Improved management pages Views, tags, and feeds can all now me managed through the "Manage" button at the top of the page. This should be helpful when performing bulk setup and overhauls of your setup Improvements Updated UI for assignments in dialogs Chip + searchable combobox for assigning views, tags, and feeds in dialogs Views and tags can be created directly from combobox UI (if no existing one matches) Manage button in header Added a "Manage" button to the header (on keyboard triggerable through m) to make the feed management page more accessible Settings dialog UI updates Renamed "Edit Profile" to "Settings" Reorganized some elements and moved them to a subsection