Update release notes with recent changes.

Htmldocs/release_notes.html

@@ -12,16 +12,20 @@
     <br><a href=http://www.apneaboard.com/wiki/index.php/OSCAR_Release_Notes>http://www.apneaboard.com/wiki/index.php/OSCAR_Release_Notes</a></p>
     <p>
     <b>Changes and fixes in OSCAR v1.X.Y</b>
-    <br>Portions of OSCAR are © 2019-2020 by
+    <br>Portions of OSCAR are © 2019-2021 by
     <i>The OSCAR Team</i></p>
     <ul>
+      <li>[new] Add support for DeVilbiss BLUE (DV6x) CPAP machines [experimental].</li>
       <li>[new] Additional Philips Respironics devices tested and fully supported:
         <ul>
           <li>DreamStation Go Auto (500G120)</li>
           <li>DreamStation Auto CPAP with A-Flex (500X140)</li>
+          <li>DreamStation BiPAP AVAPS 30 (1130X200)</li>
         </ul>
       </li>
       <li>[new] Add support for DreamStation Go humidifier Target Time setting.</li>
+      <li>[new] Add Bulgarian translation; update other languages.</li>
+      <li>[new] Improve Somnopose import options.</li>
       <li>[fix] Correct calculation of average leak rate on Welcome page.</li>
       <li>[fix] Correct installation of non-English Release Notes on Windows.</li>
       <li>[fix] About/Credits page now offers Google translations to other languages.</li>
@@ -33,6 +37,10 @@
       <li>[fix] Purge currently selected day no longer deletes bookmarks for that day.</li>
       <li>[fix] Remove warning from Chromebook when importing from previously used local folder.</li>
       <li>[fix] Update link to Contec drivers.</li>
+      <li>[fix] Fix display problems for short duration events.</li>
+      <li>[fix] Statistics headings will now be 99.5% or Max, depending on machine type and preference settings.</li>
+      <li>[fix] Mark exported Journal backup file as UTF-8.</li>
+      <li>[fix] Improve error message when unable to access OSCAR database.</li>
     </ul>
     <p>
     <b>Changes and fixes in OSCAR v1.2.0</b>