added back license file

hall.scm

@@ -15,7 +15,7 @@
   ((guix #f)
    (use-guix-specs-for-dependencies #f)
    (native-language-support #f)
-   (licensing #f)))
+   (licensing #t)))
  (files (libraries
          ((directory
            "msg"
@@ -30,6 +30,7 @@
          ((org-file "README")
           (symlink "README" "README.org")
           (text-file "HACKING")
+          (text-file "LICENSE")
           (text-file "COPYING")
           (directory "doc" ((texi-file "msg") (scheme-file "config")))
           (text-file "NEWS")