I tried adding the MyMedia.lua and MyMedia files folder with a single font file. I managed to get the font to work with Clearfont2 and a custom fontpack file, but I couldn't get it to show up at all with the other default MyMedia fonts.
I repeatedly checked the code to make sure there was no mistake, and made sure that every file was where it was supposed to be, exactly as the instructions dictate, but still nothing. So, I decided to check the SharedMedia.lua's code, and the entries were a little different.
The instructions state entries should look like this:
SML:Register("font", "my font's name", "Interface\\Addons\\SharedMedia\\MyMedia files\\myfont.ttf")
But SharedMedia.lua has them like this:
SML:Register("font", "my font's name", [["Interface\Addons\SharedMedia\MyMedia files\myfont.ttf"]])
I tried the second way (single "\"s with double brackets) and it worked. I suppose maybe the instructions file should be changed?
Edit: well after a little testing. . . I got the font to work like this, but where it did work, I had to do a /rl for it to show up. In some AddOns it would not work at all and upon a reload I get a slew of errors claiming the font is not set. Well, no idea whats up anymore =/