Put GH actions badge in README

Author: maxbrunsfeld

README.md

@@ -1,7 +1,7 @@
 tree-sitter-typescript
 ===========================
 
-[![Build Status](https://travis-ci.org/tree-sitter/tree-sitter-typescript.svg?branch=master)](https://travis-ci.org/tree-sitter/tree-sitter-typescript)
+[![Build Status](https://github.com/tree-sitter/tree-sitter-typescript/workflows/build/badge.svg)](https://github.com/tree-sitter/tree-sitter-typescript/actions?query=workflow%3Abuild)
 [![Build status](https://ci.appveyor.com/api/projects/status/rn11gs5y3tm7tuy0/branch/master?svg=true)](https://ci.appveyor.com/project/maxbrunsfeld/tree-sitter-typescript/branch/master)
 
 TypeScript and TSX grammars for [tree-sitter][].