Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/path_basename.md

@@ -0,0 +1,34 @@
+---
+title: path basename
+layout: command
+version: 0.59.0
+---
+
+Get the final component of a path
+
+## Signature
+
+```> path basename --columns --replace```
+
+## Parameters
+
+ -  `--columns {table}`: Optionally operate by column path
+ -  `--replace {string}`: Return original path with basename replaced by this string
+
+## Examples
+
+Get basename of a path
+```shell
+> '/home/joe/test.txt' | path basename
+```
+
+Get basename of a path by column
+```shell
+> [[name];[/home/joe]] | path basename -c [ name ]
+```
+
+Replace basename of a path
+```shell
+> '/home/joe/test.txt' | path basename -r 'spam.png'
+```
+