patch 8.2.3368: not all Racket files are recognized

Problem:    Not all Racket files are recognized.
Solution:   Also recognize .rktl and .rktd files. (Doug Kearns)
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index bda6f3c..5463c1c 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -428,7 +428,7 @@
     \ 'sather': ['file.sa'],
     \ 'sbt': ['file.sbt'],
     \ 'scala': ['file.scala', 'file.sc'],
-    \ 'scheme': ['file.scm', 'file.ss', 'file.rkt'],
+    \ 'scheme': ['file.scm', 'file.ss', 'file.rkt', 'file.rktd', 'file.rktl'],
     \ 'scilab': ['file.sci', 'file.sce'],
     \ 'screen': ['.screenrc', 'screenrc'],
     \ 'sexplib': ['file.sexp'],
diff --git a/src/version.c b/src/version.c
index 619c840..a439d99 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3368,
+/**/
     3367,
 /**/
     3366,