Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/dfr_contains.md

@@ -0,0 +1,23 @@
+---
+title: dfr contains
+layout: command
+version: 0.59.0
+---
+
+Checks if a pattern is contained in a string
+
+## Signature
+
+```> dfr contains (pattern)```
+
+## Parameters
+
+ -  `pattern`: Regex pattern to be searched
+
+## Examples
+
+Returns boolean indicating if pattern was found
+```shell
+> [abc acb acb] | dfr to-df | dfr contains ab
+```
+