Replace Azure Pipeline with Github Action status badge.

Author: lemmy

README.md

@@ -31,4 +31,4 @@ We take the discretion to approve or reject submissions at our will.
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-[![Build Status](https://dev.azure.com/tlaplus/tlaplus/_apis/build/status/tlaplus.CommunityModules?branchName=master)](https://dev.azure.com/tlaplus/tlaplus/_build/latest?definitionId=4&branchName=master)
+![CI](https://github.com/tlaplus/CommunityModules/workflows/CI/badge.svg)