Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/export_env.md

@@ -0,0 +1,17 @@
+---
+title: export env
+layout: command
+version: 0.59.0
+---
+
+Export a block from a module that will be evaluated as an environment variable when imported.
+
+## Signature
+
+```> export env (name) (block)```
+
+## Parameters
+
+ -  `name`: name of the environment variable
+ -  `block`: body of the environment variable definition
+