runtime(csv): include a simple csv filetype and syntax plugin

fixes: #15038

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

runtime/ftplugin/csv.vim

@@ -0,0 +1,23 @@
+vim9script
+
+# Maintainer: Maxim Kim <habamax@gmail.com>
+# Last Update: 2024-06-18
+
+if !exists("b:csv_delimiter")
+    # detect delimiter
+    var delimiters = ",;\t|"
+
+    var max = 0
+    for d in delimiters
+        var count = getline(1)->split(d)->len() + getline(2)->split(d)->len()
+        if count > max
+            max = count
+            b:csv_delimiter = d
+        endif
+    endfor
+endif
+
+if exists("b:did_ftplugin")
+    finish
+endif
+b:did_ftplugin = 1