gnu: emacs-mct: Add Info manual.

* gnu/packages/emacs-xyz.scm (emacs-mct): Add Info manual.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/emacs-xyz.scm

@@ -1009,7 +1009,20 @@ (define-public emacs-mct
               (sha256
                (base32 "0714n5nim0hyd5jywvvddka2gi2bhi1vkrbhx75mdn8h50r688kq"))
               (file-name (git-file-name name version))))
+    (native-inputs (list texinfo))
     (build-system emacs-build-system)
+    (arguments
+     (list
+      #:phases
+      #~(modify-phases %standard-phases
+          (add-after 'install 'makeinfo
+            (lambda _
+              (invoke "emacs"
+                      "--batch"
+                      "--eval=(require 'ox-texinfo)"
+                      "--eval=(find-file \"README.org\")"
+                      "--eval=(org-texinfo-export-to-info)")
+              (install-file "mct.info" (string-append #$output "/share/info")))))))
     (home-page "https://protesilaos.com/emacs/mct")
     (synopsis "Enhancement of the default Emacs minibuffer completion UI")
     (description "Minibuffer and Completions in Tandem, also known as MCT, or
@@ -1018,7 +1031,8 @@ (define-public emacs-mct
 framework.  The idea is to make the presentation and overall functionality be
 consistent with other popular, vertically aligned completion UIs while
 leveraging built-in functionality.")
-    (license license:gpl3+)))
+    (license (list license:gpl3+
+                   license:fdl1.3+)))) ; GFDLv1.3+ for the manual
 
 (define-public emacs-minions
   (package