Add markdown linting (without breaking the site this time!)

manuscript/recipes/gitlab-runner.md

@@ -24,7 +24,7 @@ Existing:
 
 We'll need several directories to bind-mount into our runner containers, so create them in `/var/data/gitlab`:
 
-```
+```bash
 mkdir -p /var/data/gitlab/runners/{1,2}
 ```
 
@@ -66,7 +66,7 @@ From your GitLab UI, you can retrieve a "token" necessary to register a new runn
 
 Sample runner config.toml:
 
-```
+```ini
 concurrent = 1
 check_interval = 0
 
@@ -94,5 +94,4 @@ Launch the GitLab Runner stack by running `docker stack deploy gitlab-runner -c
 [^1]: You'll note that I setup 2 runners. One is locked to a single project (_this cookbook build_), and the other is a shared runner. I wanted to ensure that one runner was always available to run CI for this project, even if I'd tied up another runner on something heavy-duty, like a container build. Customize this to your use case.
 [^2]: Originally I deployed runners in the same stack as GitLab, but I found that they would frequently fail to start properly when I launched the stack. I think that this was because the runners started so quickly (_and GitLab starts **sooo** slowly!_), that they always started up reporting that the GitLab instance was invalid or unavailable. I had issues with CI builds stuck permanently in a "pending" state, which were only resolved by restarting the runner. Having the runners deployed in a separate stack to GitLab avoids this problem.
 
-
---8<-- "recipe-footer.md"
+--8<-- "recipe-footer.md"