[Freeswitch-docs] Introduction and wiki access

[William McCall]

Hi all--

Long time admirer/user and new contributor here looking to collab on
some doc stuff.

Specifically, I'm looking to document the TDD/TTY functionality in span_dsp.

LMK how I can best contribute this documentation to the wiki. I've got
the style guidelines nearby, so newbie mistakes should be low
hopefully :)

Thanks!

-- 
William McCall