patch 9.1.0953: filetype: APKBUILD files not correctly detected

Problem:  filetype: APKBUILD files not correctly detected
Solution: detect 'APKBUILD' files as apkbuild filetype,
          include a apkbuild syntax script (which basically
          just sources the sh.vim syntax file)
          (Hugo Osvaldo Barrera)

Vim plugins (e.g.: ALE, nvim-lspconfig, etc) rely on filetype to
determine which integrations/helpers are applicable. They expect
filetype=apkbuild for APKBUILD files.

On the other hand, plugins also enable bash-specific linters and
functionality when filetype=bash, but APKBUILD files are POSIX sh, not
bash, so these often provide bogus results.

Change the filetype for APKBUILD to a 'apkbuild', so that tools and
ftplugin can properly target these files. This filetype will use the
existing `sh` syntax rules, since these are applicable for them.

Signed-off-by: Hugo Osvaldo Barrera' via vim_dev <vim_dev@googlegroups.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index dc7a029..51498fd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    953,
+/**/
     952,
 /**/
     951,