update README

Author: lasconic

README.md

@@ -1,10 +1,17 @@
-This is a plugin for MuseScore 1.2 to add harmonica tablature notation below the notes.
-It currently supports the Hohner Highlander only, for both side (A highlander and D).
+This is a plugin for MuseScore 1.2 to add harmonica tablature notation below the notes. It currently supports
+  
+ * the Hohner Highlander only, for both side, A highlander and D - [Reference](http://musescore.org/sites/musescore.org/files/Hohner%20Highlander%20scale.jpg)
+ * Lee Oskar, Diatonic C - [Reference](http://musescore.org/sites/musescore.org/files/Lee%20Oscar%20C.jpg)
+
 If you want to have your harmonica added to the it, please contact me, or better, do a pull request.
 
-- + is for blow
-- - is for draw
 
-For more info see 
+##Convention
+* "+" is for blow
+* "-" is for draw
+
+Bends, over blow, over draw may be supported if it's the only way to play the note. 
+If there are two holes for one note, a choice has been made. 
 
-   - The official project page http://musescore.org/en/project/harmonicatablature
+##More info
+See the official [project page](http://musescore.org/en/project/harmonicatablature)