Auto-generate markdown command docs (#4451)

* Finish updating

* a couple improvements

* Update renames

* cleanup examples

docs/commands/which.md

@@ -1,105 +1,25 @@
-# which
+---
+title: which
+layout: command
+version: 0.59.0
+---
 
-Finds a program file.
+Finds a program file, alias or custom command.
 
-Usage:
-  > which <application> {flags}
+## Signature
+
+```> which (application) ...rest --all```
 
 ## Parameters
 
-- application: the name of the command to find the path to
-
-## Flags
-
-- --all: list all executables
+ -  `application`: application
+ -  `...rest`: additional applications
+ -  `--all`: list all executables
 
 ## Examples
 
-`which` finds the location of an executable:
-
+Find if the 'myapp' application is available
 ```shell
-> which python
-─────────┬─────────────────
- arg     │ python
- path    │ /usr/bin/python
- builtin │ false
-─────────┴─────────────────
+> which myapp
 ```
 
-```shell
-> which cargo
-─────────┬────────────────────────────
- arg     │ cargo
- path    │ /home/bob/.cargo/bin/cargo
- builtin │ false
-─────────┴────────────────────────────
-```
-
-`which` will identify nushell commands:
-
-```shell
-> which ls
-─────────┬──────────────────────────
- arg     │ ls
- path    │ nushell built-in command
- builtin │ true
-─────────┴──────────────────────────
-```
-
-```shell
-> which which
-─────────┬──────────────────────────
- arg     │ which
- path    │ nushell built-in command
- builtin │ true
-─────────┴──────────────────────────
-```
-
-Passing the `all` flag identifies all instances of a command or binary
-
-```shell
-> which ls --all
-───┬─────┬──────────────────────────┬─────────
- # │ arg │ path                     │ builtin
-───┼─────┼──────────────────────────┼─────────
- 0 │ ls  │ nushell built-in command │ true
- 1 │ ls  │ /bin/ls                  │ false
-───┴─────┴──────────────────────────┴─────────
-```
-
-`which` will also identify local binaries
-
-```shell
-> touch foo
-> chmod +x foo
-> which ./foo
-─────────┬────────────────────────────────
- arg     │ ./foo
- path    │ /Users/josephlyons/Desktop/foo
- builtin │ false
-─────────┴────────────────────────────────
-```
-
-`which` also identifies aliases
-
-```shell
-> alias e = echo
-> which e
-───┬─────┬───────────────┬─────────
- # │ arg │     path      │ builtin
-───┼─────┼───────────────┼─────────
- 0 │ e   │ Nushell alias │ false
-───┴─────┴───────────────┴─────────
-```
-
-and custom commands
-
-```shell
-> def my_cool_echo [arg] { echo $arg }
-> which my_cool_echo
-───┬──────────────┬────────────────────────┬─────────
- # │     arg      │          path          │ builtin
-───┼──────────────┼────────────────────────┼─────────
- 0 │ my_cool_echo │ Nushell custom command │ false
-───┴──────────────┴────────────────────────┴─────────
-```