Made first progress on Functions section

COVER.md
src/SDL_AddEventWatch.3
src/SDL_AddHintCallback.3
src/SDL_AddTimer.3
src/SDL_AllocFormat.3
src/SDL_AllocPalette.3
src/SDL_AllocRW.3
src/SDL_AndroidGetActivity.3
src/SDL_FunctionTemplate

Started to gain benefit of previous sections which have been done in completing Functions section whenever I need to refer back to certain struct or don't know about certain references.