added home and global feed, home will try to show timeline with
all followed contacts and fallback to global if there are no
followees.
in a future commit global tab could become search and have a
search field at the top.
this creates a kind 3 event that includes a list of profiles that
the user is following.
the feed is still the public global feed and individual feed with
only events from followed pubkeys will be added in the next commit.