Autogenerate missing docs (#3514)

* Autogenerate missing docs

* Update ansi.md

* Rename question mark command docs

* Delete empty?.md

docs/commands/str-snake-case.md

@@ -0,0 +1,20 @@
+# str snake-case
+converts a string to snake_case
+
+## Usage
+```shell
+> str snake-case ...args {flags} 
+ ```
+
+## Parameters
+* ...args: optionally convert text to snake_case by column paths
+
+## Flags
+* -h, --help: Display this help message
+
+## Examples
+  convert a string to snake_case
+```shell
+> echo 'NuShell' | str snake-case
+ ```
+