Update README.md for vscode extension (#229)

src/Clients/PullRequestQuantifier.VsCode.Client/README.md

@@ -4,6 +4,16 @@
 
 Install the VSCode extension either through the browser or from VSCode itself.
 
+### Using the command line:
+
+```bash
+code --install-extension ms-1es.pull-request-quantifier
+```
+
+### Using the vscode UI
+
+Search for `ms-1es.pull-request-quantifier` 
+
 ## Usage
 
 Whenever a file is saved in VSCode, if that file is part of a git repo, the PullRequestQuantifier extension will evaluate changes