README.md in discourse_theme-0.8.0 vs README.md in discourse_theme-0.9.0

@@ -34,9 +34,24 @@
 
 ### `discourse_theme upload PATH`
 
 Uploads a theme to the server. Requires the theme to have been previously synchronized via `watch`.
 
+### `discourse_theme rspec PATH`
+
+Runs the [RSpec](https://rspec.info/) system tests under the `spec` folder in the designated theme directory.
+
+On the first run for the given directory, you will be asked if you'll like to use a local Discourse repository to run the tests.
+
+If you select 'Y' and proceeds to configure the path to the local Discourse repository, the tests will be ran using the local Discourse development environment provided by the local Discourse repository. Note that you'll have to set up the local test environment before
+the tests can be ran successfully.
+
+If the 'n' option is selected, the tests will run in a Docker container created using the [`discourse/discours_test:release`](https://hub.docker.com/r/discourse/discourse_test) Docker image. Note that this requires [Docker](https://docs.docker.com/engine/install/) to be installed.
+
+When the `--headless` option is used, a local installation of the [Google Chrome browser](https://www.google.com/chrome/) is required.
+
+Run `discourse_theme --help` for more usage details.
+
 ## Contributing
 
 Bug reports and pull requests are welcome at [Meta Discourse](https://meta.discourse.org). This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.
 
 ## License