propsed change for up-for-grabs label

see dotnet/corefx#17533

README.md

@@ -81,7 +81,7 @@ Some of the best ways to contribute are to try things out, file bugs, and join i
 * [How to Contribute](https://github.com/dotnet/roslyn/wiki/Contributing-Code)
 * [Pull requests](https://github.com/dotnet/roslyn/pulls): [Open](https://github.com/dotnet/roslyn/pulls?q=is%3Aopen+is%3Apr)/[Closed](https://github.com/dotnet/roslyn/pulls?q=is%3Apr+is%3Aclosed)
 
-Looking for something to work on? The list of [up for grabs issues](https://github.com/dotnet/roslyn/issues?q=is%3Aopen+is%3Aissue+label%3A%22Up+for+Grabs%22) is a great place to start.
+Looking for something to work on? The list of [up for grabs issues](https://github.com/dotnet/roslyn/labels/up-for-grabs) is a great place to start.
 
 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.