Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/query_xml.md

@@ -0,0 +1,16 @@
+---
+title: query xml
+layout: command
+version: 0.59.0
+---
+
+execute xpath query on xml
+
+## Signature
+
+```> query xml (query)```
+
+## Parameters
+
+ -  `query`: xpath query
+