Fix CONTRIBUTING.md to reflect changes to build process.

Author: jcreedcmu

CONTRIBUTING.md

@@ -32,85 +32,29 @@ Here are a few things you can do that will increase the likelihood of your pull
 Make sure you have a fairly recent version of vscode (>1.32) and are using nodejs
 version >=v10.13.0. (Tested on v10.15.1 and v10.16.0).
 
-This repo uses [Rush](https://rushjs.io) to handle package management, building, and other
-operations across multiple projects. See the Rush "[Getting started as a developer](https://rushjs.io/pages/developer/new_developer/)" docs
-for more details.
-
-If you plan on building from the command line, it's easiest if Rush is installed globally:
-
-```shell
-npm install -g @microsoft/rush
-```
-
-To get started, run:
-
-```shell
-rush update && rush build
-```
-
-Note that when you run the `rush` command from the globally installed version, it will examine the
-`rushVersion` property in the repo's `rush.json`, and if it differs from the globally installed
-version, it will download, cache, and run the version of Rush specified in the `rushVersion`
-property.
-
-A few more things to know about using rush:
-
-* Avoid running `npm` for any commands that install/link dependencies
-* Instead use the *rush* equivalent: `rush add <package>`, `rush update`, etc.
-* If you plan on only building via VS Code tasks, you don't need Rush installed at all, since those
-tasks run `common/scripts/install-run-rush.js` to bootstrap a locally installed and cached copy of
-Rush.
-
 ### Building
 
-#### Installing all packages (instead of `npm install`)
-
-After updating any `package.json` file, or after checking or pulling a new branch, you need to
-make sure all the right npm packages are installed, which you would normally do via `npm install` in
-a single-project repo. With Rush, you need to do an "update" instead:
-
-##### From VS Code
+#### Installing all packages
 
-`Terminal > Run Task... > Update`
+Run
 
 ##### From the command line
 
 ```shell
-rush update
+npm install
 ```
 
-#### Building all projects (instead of `gulp`)
+from the directory `extensions/ql-vscode`.
 
-Rush builds all projects in the repo, in dependency order, building multiple projects in parallel
-where possible. By default, the build also packages the extension itself into a .vsix file in the
-`dist` directory. To build:
-
-##### From VS Code
-
-`Terminal > Run Build Task...` (or just `Ctrl+Shift+B` with the default key bindings)
-
-##### From the command line
+#### Building
 
 ```shell
-rush build --verbose
+gulp
 ```
 
-#### Forcing a clean build
-
-Rush does a reasonable job of detecting on its own which projects need to be rebuilt, but if you need to
-force a full rebuild of all projects:
-
 ##### From VS Code
 
-`Terminal > Run Task... > Rebuild`
-
-##### From the command line
-
-```shell
-rush rebuild --verbose
-```
-
-Note that `rush rebuild` performs a complete rebuild, whereas `rush build` performs an incremental build and in many cases will not need to do anything at all.
+`Terminal > Run Build Task...` (or just `Ctrl+Shift+B` with the default key bindings)
 
 ### Installing