cloudapp: add README (#8229)

plugins/cloudapp/README.md

@@ -0,0 +1,24 @@
+# CloudApp plugin
+
+[CloudApp](https://www.getcloudapp.com) brings screen recording, screenshots, and GIF creation to the cloud, in an easy-to-use enterprise-level app. The CloudApp plugin allows you to upload a file to your CloadApp account from the command line.
+
+To use it, add `cloudapp` to the plugins array of your `~/.zshrc` file:
+
+```
+plugins=(... dash)
+```
+
+## Requirements
+
+1. [Aaron Russell's `cloudapp_api` gem](https://github.com/aaronrussell/cloudapp_api#installation)
+
+2. That you set your CloudApp credentials in `~/.cloudapp` as a simple text file like below:
+   ```
+   email
+   password
+   ```
+
+## Usage
+
+- `cloudapp <filename>`: uploads `<filename>` to your CloudApp account, and if you're using
+  macOS, copies the URL to your clipboard.