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>
