- Update the 12.1-RELEASE schedule to reflect releng/12.1 had branched,

and the BETA1 builds are in flight.
- Document __FreeBSD_version numbers 1201000 and 1201500.
- Add releng/12.1 to the list of branches in the releng page.

Approved by:	re (implicit)
Sponsored by:	Rubicon Communications, LLC (Netgate)

en_US.ISO8859-1/htdocs/releases/12.1R/schedule.xml

@@ -74,7 +74,7 @@
       <tr>
 	<td>&local.branch.releng; branch</td>
 	<td>20&nbsp;September&nbsp;2019</td>
-	<td>-</td>
+	<td>20&nbsp;September&nbsp;2019</td>
 	<td>Subversion branch created; future release engineering
 	  proceeds on this branch.</td>
       </tr>
@@ -82,7 +82,7 @@
       <tr>
 	<td>BETA1 builds begin</td>
 	<td>20&nbsp;September&nbsp;2019</td>
-	<td>-</td>
+	<td>20&nbsp;September&nbsp;2019</td>
 	<td>First beta test snapshot.</td>
       </tr>
 

en_US.ISO8859-1/htdocs/releng/index.xml

@@ -96,6 +96,13 @@
       <td>Development branch for FreeBSD 12-STABLE.</td>
     </tr>
 
+    <tr>
+      <td><tt>releng/12.1</tt></td>
+      <td>Frozen</td>
+      <td>&contact.re;</td>
+      <td>FreeBSD 12.1 supported errata fix branch.</td>
+    </tr>
+
     <tr>
       <td><tt>releng/12.0</tt></td>
       <td>Frozen</td>