Minor bug fix: Removed "video clue" in clues.txt

Sample clues still referenced a video clue, despite that functionality
being removed. The text has been replaced.
Rem: Sample video

Video folder in /res/ also deleted.
Add: Sample clue reading audio
Update: Audio clue readings fully implemented

Docs (instructions) also completed in resmaps.

/res/text/clues.txt changed to add sample audio-reading clues.
Update: main

do_intro and do_scroll were commented out of main for testing purposes
in the previous commit. They have been uncommented.
Bug fix: Clue readings

pygame.time.wait() no longer used to wait until audio finished. Game now
continues to iterate through primary loop until sound finished, keeping
with standard practice for states, and fixing the problem where the game
would momentarily freeze if the window was moved while a clue reading is
playing.
Docs update: todo
Docs add: /dev/milestones.txt
Update: /dev/state_flow.png

Updated for new states regarding clue readings.
Update: resmaps now separates customizable maps

To help prevent a customizing user from accidentally breaking the game
by altering necessary maps, these maps are moved to the bottom of the
file and kept separate from what the user can touch.
Add: /res/sounds/sample_music.ogg

Will be used to test audio as clue media.
Update: MEDIA removed.

The old customization system of adding a file in resmaps.py, then adding
its name to MEDIA in /ui/config.py was needlessly complex. Keys of
(category, row) are now used to link an image (later audio files as
well) to a clue in resmaps.py.
Docs update: Audio reading information in README

Also added to milestones.
Upd: New audio clue states

Also updated state_flow to reflect these new states.
Upd: AudioPlayer handles audio & read for 1 clue

A single clue can now have an audio reading, and audio as clue media.

In JeopAudioPlayer, all clue readings now referenced by (cat, row, 'cr')
Upd: Audio clues implemented

Added sample audio clue at (0, 4)
Upd: Instructions in resmaps, sample clues

Sample audio clue added to every category.
Docs: Update to v0.9

Will merge into master after this commit.