Update README with brief instructions. (#101)

Author: varungandhi-src

README.md

@@ -2,4 +2,64 @@
 
 LSIF indexer for TypeScript and JavaScript.
 
+## Quick start
+
+### Installation
+
+```sh
+npm install -g @sourcegraph/lsif-typescript
+```
+
+### Indexing a TypeScript project
+
+Navigate to the project root, containing `tsconfig.json`.
+
+```sh
+npm install # or yarn install
+lsif-typescript index
+```
+
+### Indexing a JavaScript project
+
+Navigate to the project root, containing `package.json`.
+
+```sh
+npm install # or yarn install
+lsif-typescript index --infer-tsconfig
+```
+
+To improve the quality of indexing results for JavaScript,
+consider adding `@types/*` packages as `devDependencies` in `package.json`.
+
+### Index a TypeScript project using Yarn workspaces
+
+Navigate to the project root, containing `package.json`.
+
+```
+npm install # or yarn install
+lsif-typescript index --yarn-workspaces
+```
+
+### Indexing in CI
+
+Add the following run steps to your CI pipeline:
+
+```sh
+npm install -g @sourcegraph/lsif-typescript
+npm install # or yarn install
+lsif-typescript index
+# From https://github.com/sourcegraph/src-cli/
+curl -L https://sourcegraph.com/.api/src-cli/src_linux_amd64 -o /usr/local/bin/src
+chmod +x /usr/local/bin/src
+# Upload index with any necessary tokens (shown here using GitHub workflow syntax)
+src lsif upload -github-token='${{ secrets.GITHUB_TOKEN }}' -no-progress
+```
+
+For more examples, see the
+[Sourcegraph docs](https://docs.sourcegraph.com/code_intelligence/how-to/index_a_typescript_and_javascript_repository).
+
+## Contributing
+
 See [Development.md](./Development.md) for docs on how to work on this project.
+
+Contributors should follow the [Sourcegraph Community Code of Conduct](https://handbook.sourcegraph.com/company-info-and-process/community/code_of_conduct/).