doc(pwsh): add info about linting and fmt

powershell/README.md

@@ -5,6 +5,21 @@ tagline: |
   PowerShell Core is a cross-platform (Windows, Linux, and macOS) automation and configuration tool/framework.
 ---
 
+To update or switch versions, run `webi pwsh@stable` (or `@v7.4`, `@beta`, etc).
+
+### Files
+
+These are the files / directories that are created and/or modified with this
+install:
+
+```text
+~/.config/envman/PATH.env
+~/.local/opt/pwsh/
+~/.local/share/powershell/Modules
+```
+
+## Cheat Sheet
+
 > The core benefit of running `pwsh` on Mac or Linux is that you get a way to
 > debug Windows scripts without having to boot up Windows.
 
@@ -12,13 +27,39 @@ For example, if you want to create a `curl.exe -A "windows" | powershell` script
 for Windows (as we do), it's helpful to be able to do some level of debugging on
 other platforms.
 
-<!--
-For example, if you wanted to install Node.js with powershell and
-webinstall.dev, you can:
+### How to Use PowerShell with Vim
 
-```cmd
-curl.exe -s https://webi.ms/node@lts | powershell
+Assuming you have [vim-ale](../vim-ale/) installed - which is included with
+[vim-essentials](../vim-essentials/) - all you need to do is install the
+`PSScriptAnalyzer` module.
+
+See the "Lint & Fmt" section below.
+
+### How to Lint & Fmt ps1 Files
+
+You must install `PSScriptAnalyzer`. Then you can use `Invoke-ScriptAnalyzer`
+and `Invoke-Formatter`
+
+```sh
+pwsh -Command "Install-Module -Name PSScriptAnalyzer -Scope CurrentUser -AllowClobber"
 ```
--->
 
-<!-- TODO if, pipe, function -->
+To lint:
+
+```sh
+my_ps1='./my-file.ps1'
+pwsh -Command "Invoke-ScriptAnalyzer -Fix -ExcludeRule PSAvoidUsingWriteHost, PSUseDeclaredVarsMoreThanAssignment -Path \"$my_ps1\""
+```
+
+To fmt:
+
+```sh
+my_ps1='./my-file.ps1'
+my_text="$(
+    pwsh -Command "Invoke-Formatter -ScriptDefinition (Get-Content -Path \"$my_ps1\" -Raw)"
+)"
+printf '%s\n' "${my_text}" > "${my_ps1}"
+```
+
+Note: it is _several hundred times faster_ to lint and fmt from a native
+PowerShell script than from invoking `pwsh -Command` each time.