runtime(odin): include ftplugin, syntax and indent script (#13867)

Note for Neovim Contributors: this is bundled as Vim9 Script. If you want to use this on Neovim, you need to convert the Vim9 scripts to Vim Script or Lua or leave it out.

Signed-off-by: Maxim Kim <habamax@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/ftplugin/odin.vim

@@ -0,0 +1,20 @@
+vim9script
+
+# Vim filetype plugin file
+# Language: Odin
+# Maintainer: Maxim Kim <habamax@gmail.com>
+# Website: https://github.com/habamax/vim-odin
+# Last Change: 2024-01-15
+
+if exists("b:did_ftplugin")
+    finish
+endif
+b:did_ftplugin = 1
+
+b:undo_ftplugin = 'setlocal commentstring<'
+      \ .. '| setlocal comments<'
+      \ .. '| setlocal suffixesadd<'
+
+setlocal suffixesadd=.odin
+setlocal commentstring=//%s
+setlocal comments=s1:/*,mb:*,ex:*/,://