gitignore: Ignore all folders beginning with "build"
gitignore: Ignore all folders beginning with "build"

emil-e/rapidcheck,emil-e/rapidcheck,whoshuu/rapidcheck,emil-e/rapidcheck,whoshuu/rapidcheck,tm604/rapidcheck,unapiedra/rapidfuzz,unapiedra/rapidfuzz,tm604/rapidcheck,whoshuu/rapidcheck,tm604/rapidcheck,unapiedra/rapidfuzz