fix: add doc for SD_TEMPLATE env vars (#166)

* fix: add doc for SD_TEMPLATE env vars

* Update environment-variables.md

docs/user-guide/environment-variables.md

@@ -35,6 +35,8 @@ _Note: Environment variables set in one job cannot be accessed in another job. T
 | SD_BUILD_ID | Build number (e.g.: 1, 2, etc) |
 | SD_PULL_REQUEST | Pull Request number (blank if non-PR) |
 | SD_TOKEN | JWT token for the build |
+| SD_TEMPLATE_NAME | Name of the template the job is using (blank if not using template) |
+| SD_TEMPLATE_VERSION | Version of the template the job is using (blank if not using template)|
 
 ## Directories
 
@@ -64,6 +66,7 @@ _Note: Environment variables set in one job cannot be accessed in another job. T
 | SD_API_URL | Link to the Screwdriver API URL |
 | SD_STORE_URL | Link to the Screwdriver Store URL |
 
+
 ## Continuous Integration
 
 | Name | Value |