Add a category hiding for the home page

[maelk]

This PR is rebased on #26 .

This PR implements a hiding feature that allows a user to hide some of the categories from the home page. This is configured via settings -> Hidden types. This commit also moves the URL and token input fields into their own pages to keep a lean settings page.

A reload of the app is needed when the hidden categories are modified for it to take effect.

Settings page (top):

Settings page (bottom):

URL input field:

Hidden categories (top):

Hidden categories (bottom):