fix(lib): doom/reload: on Windows

- cmd.exe chokes on the space in "C:\Program Files\...", but more
  importantly, doom.ps1 should be invoked with powershell, not cmd.exe.
- Windows has pwsh.exe and powershell.exe, which, while not identical,
  are close enough for our purposes, but needed to be accounted for.

Fix: #8098

bin/doom.ps1

@@ -1,12 +1,19 @@
 # bin/doom.ps1
+# TODO: Use magic shebang (polyglot)?
 
-if (!(Get-Command -Erroraction silentlycontinue emacs.exe)) {
-    echo "Couldn't find emacs.exe in your PATH."
-    exit 1
+function Executable-Find {
+    foreach ($exe in $args) {
+        if ($exe) {
+            $path = Get-Command $exe -ErrorAction SilentlyContinue
+            if ($path) { return $path.Path; }
+        }
+    }
+    throw "Could not find in $PATH: $($args -join ', ')"
 }
 
+$emacs = if ($env:EMACS) { $env:EMACS } else { Executable-Find "emacs.exe" }
+$pwsh = Executable-Find "pwsh.exe" "powershell.exe"
 $doom = "$PSScriptRoot/doom"
-$emacs = if ($env:EMACS) { $env:EMACS } else { (Get-Command emacs.exe).Path }
 $oldemacsdir = $env:EMACSDIR
 
 try {
@@ -24,7 +31,8 @@ try {
 
     & $emacs -q --no-site-file --batch --load "$doom" -- --no-color $args
     if ($LASTEXITCODE -eq 254) {
-        & pwsh "$($env:temp)\doom.$($env:__DOOMPID).$($env:__DOOMSTEP).ps1" $PSCommandPath $args
+        # TODO: Use Invoke-Command instead?
+        & $pwsh "$($env:temp)\doom.$($env:__DOOMPID).$($env:__DOOMSTEP).ps1" $PSCommandPath $args
         $exit = $LASTEXITCODE
     }
     exit $exit