Add more choices to name the branch for docs only tests

http://rubular.com/r/51mKdLm6RF

Former-commit-id: 0c59aa0a

.gitlab-ci.yml

@@ -75,7 +75,7 @@ stages:
 # https://docs.gitlab.com/ce/development/writing_documentation.html#testing
 .except-docs: &except-docs
   except:
-    - /^docs\/.*/
+    - /(^docs[\/-].*|.*-docs$)/
 .rspec-knapsack: &rspec-knapsack
   stage: test
@@ -309,7 +309,7 @@ downtime_check:
     - master
     - tags
     - /^[\d-]+-stable(-ee)?$/
-    - /^docs\/*/
+    - /(^docs[\/-].*|.*-docs$)/
 ee_compat_check:
   <<: *rake-exec

doc/development/writing_documentation.md

@@ -78,14 +78,21 @@ Currently GitLab docs use Redcarpet as [markdown](../user/markdown.md) engine, b
 We try to treat documentation as code, thus have implemented some testing.
 Currently, the following tests are in place:
-1. `docs:check:links`: Check that all internal (relative) links work correctly
-1. `docs:check:apilint`: Check that the API docs follow some conventions
+1. `docs lint`: Check that all internal (relative) links work correctly and
+   that all cURL examples in API docs use the full switches.
 If your contribution contains **only** documentation changes, you can speed up
-the CI process by prepending to the name of your branch: `docs/`. For example,
-a valid name would be `docs/update-api-issues` and it will run only the docs
-tests. If the name is `docs-update-api-issues`, the whole test suite will run
-(including docs).
+the CI process by following some branch naming conventions. You have three
+choices:
+
+| Branch name | Valid example |
+| ----------- | ------------- |
+| Starting with `docs/` | `docs/update-api-issues`     |
+| Starting with `docs-` | `docs-update-api-issues`     |
+| Ending in `-docs`     | `123-update-api-issues-docs` |
+
+If your branch name matches any of the above, it will run only the docs
+tests. If it doesn't, the whole test suite will run (including docs).
 ---