Add electron readme

packages/electron/README.md

@@ -0,0 +1,46 @@
+# @padloc/electron
+
+Padloc Desktop app, built with [Electron](https://www.electronjs.org/)
+
+## Setup
+
+The `@padloc/electron` package is meant to be used from within the
+[Padloc monorepo](../../README.md).
+
+```sh
+git clone git@github.com:padloc/padloc.git
+cd padloc
+npm ci
+cd packages/electron
+```
+
+## Building
+
+To build the app, run:
+
+```sh
+npm run build
+```
+
+The resulting build can be fund in the `dist` folder.
+
+### Build options
+
+All build options are provided as environment variables:
+
+| Variable Name   | Description                                        | Default  |
+| --------------- | -------------------------------------------------- | -------- |
+| `PL_SERVER_URL` | URL to the [server component](../server/README.md) | `./dist` |
+
+## Development
+
+For rapid development, there is also dev mode:
+
+```sh
+npm run dev
+```
+
+## Contributing
+
+For info on how to contribute to Padloc, please refer to the
+[monorepo readme](../../README.md#contributing).