Adding rumble info to images/README, moving melee analog values to #defines and optional neutral SOCD for melee.

[SergioPDhe]

Some useful changes I (user 'Mr. Potatobread' on the discord) made when working on my fork. The functionality of the code should be unchanged.

Rumble info:

• line added to README saying rumble is on GP11 and warning users of its potential misuse.
• images altered to add rumble pin (currently doesn't look great - I couldn't find the font used in the original images)

Moving Melee analog values to defines:

• added "melee_values.hpp" with definitions for all control-stick/c-stick/analogL&R values in "melee_F1.cpp"
• changed "melee_F1.cpp" to use said defines
• double-checked that values are unchanged from original fw

[SergioPDhe]

Added optional support for neutral SOCD

• added 'bool neutralSOCD' (default value is 'false', resulting in normal 2IP function)