Lots of small improvements to the melodies exercise:
Melodies:
* The degrees are now selected individually, no longer using scales. Similarly to how it is like in the degrees exercise.
* Added the full names for each degree under the hexagons.
* Fixed score display for ES language.
* Added a hear drone option like the one present in the degrees exercise.
* You now can't get the same degree twice in a row.
* Fixed spacebar not reseting the exercise progress.
Other changes:
* Added example degrees on the fretboard like the ones in the interval exercise.
* Made the degrees and interval full text bigger so it's easier to read.
* Added ES language degree names.
* Re-ordered the exercises so that degrees come on by default as it's going to be the main focus of the application along with melodies from now on.
* Fix for some interval examples not showing up when the max fret size was set to a low number.
* Fix hold button for drone not working when interacting with it using the mouse.
* Lowered drone note volume.