Update tags in List Item

[aubundy]

• [x] When a user clicks on a tag, app should display every reading with that tag

• [x] Tag name should be displayed in Title with tag reading stats

• [x] Tag list on a List Item should be scrollable or expandable

• [x] User should be able to edit tags:

  • [x] add
  • [x] update
  • [x] delete