patch 9.1.0749: filetype: http files not recognized

Problem:  filetype: http files not recognized
Solution: detect '*.http' as http filetype, include
          http filetype plugin (Riley Bruins)

Based on the specification found
[here](https://github.com/JetBrains/http-request-in-editor-spec/blob/master/spec.md)

closes: #15762

Signed-off-by: Riley Bruins <ribru17@hotmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index 1667d21..7f39625 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -1065,6 +1065,9 @@
 au BufNewFile,BufRead *.html,*.htm,*.shtml,*.stm  call dist#ft#FThtml()
 au BufNewFile,BufRead *.cshtml			setf html
 
+" HTTP request files
+au BufNewFile,BufRead *.http			setf http
+
 " HTML with Ruby - eRuby
 au BufNewFile,BufRead *.erb,*.rhtml		setf eruby
 
diff --git a/runtime/ftplugin/http.vim b/runtime/ftplugin/http.vim
new file mode 100644
index 0000000..ca50550
--- /dev/null
+++ b/runtime/ftplugin/http.vim
@@ -0,0 +1,13 @@
+" Vim filetype plugin
+" Language:	HTTP
+" Maintainer:	Riley Bruins <ribru17@gmail.com>
+" Last Change:	2024 Sep 28
+
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+setl comments=:# commentstring=#\ %s
+
+let b:undo_ftplugin = 'setl com< cms<'