move to modules and vendor dependencies

Add dependency to pkg-config and fix some formatting issues

add contribution guidelines

add licenses all around

final commit

inverted pipes work

one pipe moving and killing the bird

one pipe moves to the left, no collision

dead dies when touches the ground

handle events and bounce

make bird fall and bounce

refactored bird code to new type

fix data race

created scene type and added animated bird

refactored to scene type