patch 9.1.0592: runtime: filetype: Mediawiki files are not recognized

Problem:  filetype: Mediawiki files are not recognized
Solution: detect "*.mw" and "*.wiki" as mediawiki filetype,
          include basic syntax and filetype plugins.
          (AvidSeeker)

closes: #15266

Signed-off-by: AvidSeeker <avidseeker7@protonmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/.github/MAINTAINERS b/.github/MAINTAINERS
index 9f9438c..eb94cb7 100644
--- a/.github/MAINTAINERS
+++ b/.github/MAINTAINERS
@@ -201,6 +201,7 @@
 runtime/ftplugin/m3build.vim		@dkearns
 runtime/ftplugin/m3quake.vim		@dkearns
 runtime/ftplugin/markdown.vim		@tpope
+runtime/ftplugin/mediawiki.vim		@avidseeker
 runtime/ftplugin/meson.vim		@Liambeguin
 runtime/ftplugin/modula2.vim		@dkearns
 runtime/ftplugin/modula3.vim		@dkearns
@@ -480,6 +481,7 @@
 runtime/syntax/mallard.vim		@jhradilek
 runtime/syntax/markdown.vim		@tpope
 runtime/syntax/mason.vim		@petdance
+runtime/syntax/mediawiki.vim		@avidseeker
 runtime/syntax/meson.vim		@Liambeguin
 runtime/syntax/modula2.vim		@dkearns
 runtime/syntax/modula2/opt/iso.vim	@trijezdci