message: document `environment_variables.git_sha`
diff: @@ -14,6 +14,9 @@ The `.lagoon.yml` file must be placed at the root of your git repository.
  ```
  docker-compose-yaml: docker-compose.yml
  +environment_variables:
  + git_sha: 'true'
  +
  tasks:
  pre-rollout:
  - run:
  @@ -77,6 +80,9 @@ This allows you to define the behaviour of the automatic creates routes (NOT the
  * `Redirect` will redirect any http requests to https
  * `None` will mean a route for http will _not_ be created, and no redirect
  +### `environment_variables.git_sha`
  +This setting allows you to enable injecting the deployed git SHA into your project as an environment variable. By default this is disabled, setting the value to `true` then sets the SHA as the environment variable `LAGOON_GIT_SHA`.
  +
  ## Tasks
  There are different type of tasks you can define, they differ when exactly they are executed in a build flow:
  