(DOCSP-13239): update os compatibility

Author: jwilliams-mongo

source/install/compatibility.txt

@@ -31,7 +31,7 @@ architecture.
    * - Debian
      - 9, 10
    * - MacOS
-     - 10.14, 10.15
+     - 10.14, 10.15, 11.0
    * - Microsoft Windows
      - 10
    * - Microsoft Windows Server
@@ -41,7 +41,7 @@ architecture.
    * - SUSE Linux Enterprise Server
      - 12, 15
    * - Ubuntu
-     - 16.04, 18.04
+     - 16.04, 18.04, 20.04
 
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