exporters/: Add legacy documentation for the Freemind exporter

exporters/freemind.org

@@ -0,0 +1,13 @@
+#+TITLE: Freemind export
+#+AUTHOR: Bastien Guerry
+
+/This page contains what the Org <8.0 manual said about the Freemind export./
+
+/You can use the Freemind export by cloning Org's git repository and checking
+out release_7.9.4/
+
+The Freemind exporter was written by Lennart Borgman.
+
+| C-c C-e m | org-export-as-freemind | Export as a Freemind mind map (myfile.org -> myfile.mm) |
+
+

exporters/index.org

@@ -15,7 +15,7 @@ core, from =contrib/= or from external Org packages.
 * Obsolete exporters
 
 - [[file:xoxo.org][XOXO]] :: Export Org files to XOXO files
-
+- [[file:freemind.org][Freemind]] :: Export Org files to Freemind files