Rewrite the test data capture section (#12046)

doc/Developing/os/Test-Units.md

@@ -21,30 +21,35 @@ make sure it is modified in a consistent manner.
 
 ## Capturing test data
 
+???+ warning "If test data already exists"
+
+    If test data already exists, but is for a different device/configuration with the same OS.  
+    Then you should use the `--variant (-v)` option to
+    specify a different variant of the OS,  
+    this will be tested completely separate from other variants.  
+    If there is only one variant, please do not specify one.
+
+### 1. Collect SNMP data
+
 `./scripts/collect-snmp-data.php` is provided to make it easy to
 collect data for tests.  Running collect-snmp-data.php with the
---hostname (-h) allows you to capture all data used to discover and
+`--hostname (-h)` allows you to capture all data used to discover and
 poll a device already added to LibreNMS.  Make sure to re-run the
 script if you add additional support. Check the command-line help for
 more options.
 
+
+### 2. Save test data
+
 After you have collected snmp data, run `./scripts/save-test-data.php`
-with the --os (-o) option to dump the post discovery and post poll
+with the `--os (-o)` option to dump the post discovery and post poll
 database entries to json files. This step requires snmpsim, if you are
 having issues, the maintainers may help you generate it from the
 snmprec you created in the previous step.
 
-Generally, you will only need to capture data once.  After you have
-the data you need in the snmprec file, you can just use
-save-test-data.php to update the database dump (json) after that.
+Generally, you will only need to collect data once.
+After you have the data you need in the snmprec file, you can just use save-test-data.php to update the database dump (json) after that.
 
-### OS Variants
-
-If test data already exists, but is for a different
-device/configuration then you should use the --variant (-v) option to
-specify a different variant of the os, this will be tested completely
-separate from other variants.  If there is only one variant, please do
-not specify one.
 
 ## Running tests
 

mkdocs.yml

@@ -16,6 +16,7 @@ markdown_extensions:
     - pymdownx.tilde
     - pymdownx.superfences
     - pymdownx.tabbed
+    - pymdownx.details
 extra_css:
     - https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css
     - librenms.css