refactor(tazjin/homepage): long overdue entry list rework

The entry list is now much more condensed. It's maybe a little *too*
condensed, but already closer to what I'm looking for.

Note: A new "note" post type has snuck in and can now be used for
random musings or comments on previous entries. Notes do not show up
in the Atom feed.

Change-Id: I920c0c7650937474b8a5f30cba78416554d523ce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8806
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

users/tazjin/blog/posts.nix

@@ -46,6 +46,7 @@
     date = 1423995834;
     content = ./posts/sick-in-sweden.md;
     oldKey = "1423995834";
+    listed = false;
   }
   {
     key = "nsa-zettabytes";