feat: add support for cmd (#3277)

* feat: add support for cmd

* add preprompt and precmd support

* add keymap support

* add info about minimum Clink version

* simplify escaping

* add handling for cmd custom commands

* add support for transient_prompt and transient_rprompt

* Revert 9140579525

This reverts commit "add support for transient_prompt and transient_rprompt"

* Apply suggestions from code review

* disable cmd shell custom commands

* any shell other than cmd can be used

* better error and correct script location

* move shell check in `map_no_escaping`

docs/README.md

@@ -16,7 +16,7 @@ footer: ISC Licensed | Copyright © 2019-present Starship Contributors
 
 # Used for the description meta tag, for SEO
 metaTitle: "Starship: Cross-Shell Prompt"
-description: Starship is the minimal, blazing fast, and extremely customizable prompt for any shell! Shows the information you need, while staying sleek and minimal. Quick installation available for Bash, Fish, ZSH, Ion, Tcsh, Elvish, Nu, Xonsh, and PowerShell.
+description: Starship is the minimal, blazing fast, and extremely customizable prompt for any shell! Shows the information you need, while staying sleek and minimal. Quick installation available for Bash, Fish, ZSH, Ion, Tcsh, Elvish, Nu, Xonsh, Cmd, and PowerShell.
 ---
 
 <div class="center">
@@ -158,3 +158,13 @@ description: Starship is the minimal, blazing fast, and extremely customizable p
 
    execx($(starship init xonsh))
    ```
+
+   #### Cmd
+
+   You need to use [Clink](https://chrisant996.github.io/clink/clink.html) (v1.2.30+) with Cmd. Add the following to a file `starship.lua` and place this file in Clink scripts directory:
+
+   ```lua
+   -- starship.lua
+
+   load(io.popen('starship init cmd'):read("*a"))()
+   ```