Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/str_starts-with.md

@@ -0,0 +1,34 @@
+---
+title: str starts-with
+layout: command
+version: 0.59.0
+---
+
+checks if string starts with pattern
+
+## Signature
+
+```> str starts-with (pattern) ...rest```
+
+## Parameters
+
+ -  `pattern`: the pattern to match
+ -  `...rest`: optionally matches prefix of text by column paths
+
+## Examples
+
+Checks if string starts with 'my' pattern
+```shell
+> 'my_library.rb' | str starts-with 'my'
+```
+
+Checks if string starts with 'my' pattern
+```shell
+> 'Cargo.toml' | str starts-with 'Car'
+```
+
+Checks if string starts with 'my' pattern
+```shell
+> 'Cargo.toml' | str starts-with '.toml'
+```
+