Update runtime files

runtime/ftplugin/ps1xml.vim

@@ -0,0 +1,34 @@
+" Vim filetype plugin file
+" Language:    Windows PowerShell
+" URL:         https://github.com/PProvost/vim-ps1
+" Last Change: 2021 Apr 02
+
+" Only do this when not done yet for this buffer
+if exists("b:did_ftplugin") | finish | endif
+
+" Don't load another plug-in for this buffer
+let b:did_ftplugin = 1
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+setlocal tw=0
+setlocal commentstring=#%s
+setlocal formatoptions=tcqro
+
+" Change the browse dialog on Win32 to show mainly PowerShell-related files
+if has("gui_win32")
+  let b:browsefilter = 
+        \ "All PowerShell Files (*.ps1, *.psd1, *.psm1, *.ps1xml)\t*.ps1;*.psd1;*.psm1;*.ps1xml\n" .
+        \ "PowerShell Script Files (*.ps1)\t*.ps1\n" .
+        \ "PowerShell Module Files (*.psd1, *.psm1)\t*.psd1;*.psm1\n" .
+        \ "PowerShell XML Files (*.ps1xml)\t*.ps1xml\n" .
+        \ "All Files (*.*)\t*.*\n"
+endif
+
+" Undo the stuff we changed
+let b:undo_ftplugin = "setlocal tw< cms< fo<" .
+      \ " | unlet! b:browsefilter"
+
+let &cpo = s:cpo_save
+unlet s:cpo_save