Submitting a PR is the simplest way to contribute a sketch, or to submit a modification to an existing sketch. It is suggested that you add your new sketch to the contributed folder in the first instance. Should you require data, that should be in the data sub-folder or a library place that in the libraries sub-folder. Any ruby files that are not the sketch should be placed in libraries sub-folder otherwise the interfere with the autorun feature. It pays to run at least run rubocop on your sketches, and pay attention to code format suggestions, reek can also be helpful (these are useful tools to use, however it is not expected that you follow all their suggestions).