Fix formatting of health check info

doc/user/admin_area/monitoring/health_check.md

@@ -4,8 +4,6 @@ type: concepts, howto
 
 # Health Check
 
-> NOTE: **Note:**
->
 > - Liveness and readiness probes were [introduced][ce-10416] in GitLab 9.1.
 > - The `health_check` endpoint was [introduced][ce-3888] in GitLab 8.8 and was
 >   be deprecated in GitLab 9.1.
@@ -33,7 +31,7 @@ With default whitelist settings, the probes can be accessed from localhost using
 
 The first endpoint, `health`, only checks whether the application server is running. It does not verify the database or other services are running. A successful response will return a 200 status code with the following message:
 
-```
+```text
 GitLab OK
 ```
 
@@ -101,7 +99,7 @@ accepted token can be found under the **Admin area ➔ Monitoring ➔ Health che
 
 The access token can be passed as a URL parameter:
 
-```
+```text
 https://gitlab.example.com/-/readiness?token=ACCESS_TOKEN
 ```