chore: rename contribute guide

CONTRIBUTING.md

@@ -0,0 +1,49 @@
+
+## Development
+
+The repository uses [Rush](https://rushjs.io/) for monorepo management.
+
+### Install Rush globally
+
+```sh
+$ npm i -g @microsoft/rush
+```
+
+### Install dependencies
+
+```sh
+$ rush update
+```
+
+### Everyday commands
+
+1. Build all packages:
+
+    ```sh
+    $ rush build
+    ```
+
+2. Watch and rebuild all libraries:
+
+    ```sh
+    $ rush build:watch
+    ```
+
+3. Start demo dev-server:
+
+    ```sh
+    $ cd apps/demo
+    $ npm run dev
+    ```
+
+Usually you need two terminals to run both 2 and 3.
+
+## FAQ
+
+### 1. WebUSB and File downloading doesn't when developing/self-host?
+
+WebUSB and Service Worker (which is used for file downloading) requires Secure Context (HTTPS or localhost).
+
+If you access the development server using IP address, that will not work.
+
+You can add a self issued SSL certificate, or add the URL to `chrome://flags/#unsafely-treat-insecure-origin-as-secure`.