Add .cl as a Common Lisp file extension.

samples/Common Lisp/sample.lisp

@@ -0,0 +1,21 @@
+;;;; -*- lisp -*-
+
+(in-package :foo)
+
+;;; Header comment.
+(defvar *foo*)
+
+(eval-when (:execute :compile-toplevel :load-toplevel)
+  (defun add (x &optional y &key z)
+    (declare (ignore z))
+    ;; Inline comment.
+    (+ x (or y 1))))
+
+#|
+Multi-line comment.
+|#
+
+(defmacro foo (x &body b)
+  (if x
+      `(1+ ,x)   ;After-line comment.
+      42))