mediatomb/gerbera: Add release note information for 21.03

Note that it made into 2 entries, one about new options in the first section.
Another in the breaking compatibility section due to the openFirewall option
which changes the behavior.

Co-authored-by: schmittlauch <t.schmittlauch+nixos@orlives.de>
(cherry picked from commit 93a80a4390499b4204cf6836bcc6cab5debecccb)

nixos/doc/manual/release-notes/rl-2105.xml

@@ -305,6 +305,24 @@
       <literal>/var/lib/powerdns</literal> to <literal>/run/pdns</literal>.
     </para>
    </listitem>
+   <listitem>
+     <para>
+       The <literal>mediatomb</literal> service is
+       now using by default the new and maintained fork
+       <literal>gerbera</literal> package instead of the unmaintained
+       <literal>mediatomb</literal> package. If you want to keep the old
+       behavior, you must declare it with:
+       <programlisting>
+       services.mediatomb.package = pkgs.mediatomb;
+       </programlisting>
+       One new option <literal>openFirewall</literal> has been introduced which
+       defaults to false. If you relied on the service declaration to add the
+       firewall rules itself before, you should now declare it with:
+       <programlisting>
+       services.mediatomb.openFirewall = true;
+       </programlisting>
+     </para>
+   </listitem>
    <listitem>
      <para>
        xfsprogs was update from 4.19 to 5.11. It now enables reflink support by default on filesystem creation.
@@ -835,6 +853,29 @@ environment.systemPackages = [
      All services should use <xref linkend="opt-systemd.services._name_.startLimitIntervalSec" /> or <literal>StartLimitIntervalSec</literal> in <xref linkend="opt-systemd.services._name_.unitConfig" /> instead.
     </para>
    </listitem>
+   <listitem>
+     <para>
+       The <literal>mediatomb</literal> service
+       declares new options. It also adapts existing options so the
+       configuration generation is now lazy. The existing option
+       <literal>customCfg</literal> (defaults to false), when enabled, stops
+       the service configuration generation completely. It then expects the
+       users to provide their own correct configuration at the right location
+       (whereas the configuration was generated and not used at all before).
+       The new option <literal>transcodingOption</literal> (defaults to no)
+       allows a generated configuration. It makes the mediatomb service pulls
+       the necessary runtime dependencies in the nix store (whereas it was
+       generated with hardcoded values before). The new option
+       <literal>mediaDirectories</literal> allows the users to declare autoscan
+       media directories from their nixos configuration:
+       <programlisting>
+       services.mediatomb.mediaDirectories = [
+         { path = "/var/lib/mediatomb/pictures"; recursive = false; hidden-files = false; }
+         { path = "/var/lib/mediatomb/audio"; recursive = true; hidden-files = false; }
+       ];
+       </programlisting>
+     </para>
+   </listitem>
    <listitem>
     <para>
      The Unbound DNS resolver service (<literal>services.unbound</literal>) has been refactored to allow reloading, control sockets and to fix startup ordering issues.