Update README.md

Adding a few more badges, including MIT license and GitHub Action marketplace

Author: IEvangelist

README.md

@@ -4,6 +4,8 @@
 [![build & test](https://github.com/dotnet/versionsweeper/actions/workflows/build-and-test.yml/badge.svg)](https://github.com/dotnet/versionsweeper/actions/workflows/build-and-test.yml)
 [![target supported version](https://github.com/dotnet/versionsweeper/actions/workflows/dog-food.yml/badge.svg)](https://github.com/dotnet/versionsweeper/actions/workflows/dog-food.yml)
 [![code-ql analysis](https://github.com/dotnet/versionsweeper/actions/workflows/codeql-analysis.yml/badge.svg)](https://github.com/dotnet/versionsweeper/actions/workflows/codeql-analysis.yml)
+[![GitHub Marketplace](https://img.shields.io/badge/marketplace-.NET%20version%20sweeper-green?colorA=24292e&colorB=97ca00&style=flat&longCache=true&logo=data:image/png;base64,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)](https://github.com/marketplace/actions/net-version-sweeper)
+[![GitHub License](https://img.shields.io/github/license/dotnet/versionsweeper)](https://github.com/dotnet/versionsweeper/blob/main/LICENSE)
 
 ## Get started