Add Common Ground project link to README

Author: bnidevs

README.md

@@ -7,6 +7,7 @@ Random Static Hosting
 - [taptrap](https://bnidevs.github.io/taptrap)
 - [Data Science Visualization](https://bnidevs.github.io/datascience_team3_f22)
 - [Text Field](https://bnidevs.github.io/text-editor)
+- [Common Ground](https://bnidevs.github.io/common-ground)
 
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