Add blank abstract factory soruce file
Add blank abstract factory soruce file

jdavis/rust-design-patterns,jdavis/rust-design-patterns,ianlet/rust-design-patterns,beni55/rust-design-patterns,beni55/rust-design-patterns,ianlet/rust-design-patterns,jdavis/rust-design-patterns,beni55/rust-design-patterns,ianlet/rust-design-patterns,jdavis/rust-design-patterns