Updated README with content from CELA

CELA has provided replacement licence files which include separate licenses for CC and code snippets. The Content Engineering Team has been tasked with replacing the license files on all existing repos. The changes to the README file must be at the top of the file to be recognized by license scanners.

README.md

@@ -1,10 +1,10 @@
-Welcome to the markdown source for Microsoft's command-line shells and console documentation.
-
 ## Microsoft Open Source Code of Conduct
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
 For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.
 
+Welcome to the markdown source for Microsoft's command-line shells and console documentation.
+
 ## File an issue
 
 [Dedicated issue repository](https://github.com/Microsoft/BashOnWindows/)