Add readme to language service (#186)

Author: dbaeumer

language-service/README.md

@@ -0,0 +1,14 @@
+# LSIF Language Service
+
+[![NPM Version](https://img.shields.io/npm/v/@vscode/lsif-language-service.svg)](https://npmjs.org/package/@vscode/lsif-language-service)
+[![NPM Downloads](https://img.shields.io/npm/dm/@vscode/lsif-language-service.svg)](https://npmjs.org/package/@vscode/lsif-language-service)
+[![Build Status](https://dev.azure.com/ms/lsif-node/_apis/build/status%2Fmicrosoft.lsif-node?branchName=main)](https://dev.azure.com/ms/lsif-node/_build/latest?definitionId=471&branchName=main)
+
+NPM module providing a language service for LSIF dumps.
+
+## History
+
+For the history please see the [main repository](https://github.com/Microsoft/lsif-node/blob/master/README.md)
+
+## License
+[MIT](https://github.com/Microsoft/lsif-node/blob/master/language-service/License.txt)