Update CONTRIBUTING.md

## Development

The repository uses [Rush](https://rushjs.io/) for monorepo management.

$ npm i -g @microsoft/rush

```

### Get code

The build script only works inside of a Git repository, so, always use `git` to clone this repository. "Download ZIP" option in GitHub code menu or source code tarball in GitHub releases will NOT work.

```sh

git clone https://github.com/yume-chan/ya-webadb.git

cd ya-webadb

```

### Install dependencies

```sh

    $ rush build

    ```

2. Watch and rebuild all libraries:

2. Watch changes and rebuild in all libraries:

    ```sh

    $ rush build:watch