runtime(abnf): include ABNF filetype plugin

closes: #17239

Signed-off-by: A4-Tacks <wdsjxhno1001@163.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/.github/MAINTAINERS b/.github/MAINTAINERS
index 13c45da..19a65c0 100644
--- a/.github/MAINTAINERS
+++ b/.github/MAINTAINERS
@@ -124,6 +124,7 @@
 runtime/doc/xxd-ru.1			@RestorerZ
 runtime/doc/xxd-ru.UTF-8.1		@RestorerZ
 runtime/ftplugin/abaqus.vim		@costerwi
+runtime/ftplugin/abnf.vim		@A4-Tacks
 runtime/ftplugin/antlr4.vim		@jiangyinzuo
 runtime/ftplugin/apache.vim		@dubgeiser
 runtime/ftplugin/arduino.vim		@k-takata
diff --git a/runtime/ftplugin/abnf.vim b/runtime/ftplugin/abnf.vim
new file mode 100644
index 0000000..4741d5f
--- /dev/null
+++ b/runtime/ftplugin/abnf.vim
@@ -0,0 +1,17 @@
+" Language:	abnf
+" Maintainer:	A4-Tacks <wdsjxhno1001@163.com>
+" Last Change:	2025-05-02
+" Upstream:	https://github.com/A4-Tacks/abnf.vim
+
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+let b:undo_ftplugin = 'setlocal iskeyword< comments< commentstring<'
+
+setlocal iskeyword=@,48-57,_,-,192-255
+setlocal comments=:;;,:;
+setlocal commentstring=;%s
+
+" vim:ts=8