update sponsors list

Author: gregsdennis

_tabs/support.md

@@ -13,6 +13,8 @@ The following kind individuals and organizations currently support Greg:
 <div class="sponsors" markdown=1>
 
 [![@xqrzd](https://github.com/xqrzd.png)](https://github.com/xqrzd)
+[![@microsoft](https://avatars.githubusercontent.com/u/6154722?v=4)](https://opensource.microsoft.com)
 [![@ChilliCream](https://github.com/ChilliCream.png)](https://github.com/ChilliCream)
+[![@mathematikoi](https://avatars.githubusercontent.com/u/83686592?u=bf8095f97dbe8328cd1f7bd02b60f1c194df5316&v=4)](https://mathematikoi.co)
 
 </div>