Revised non-copypasta help section, added one to copypasta.

* There were two "contribute" sections in non-copypasta. Merged them into one.
* Clarified options as separate bullet points, added email option.
* Added "contribute" section to copypasta.
* Added pointers from relevant points to newly created "contribute" section in copypasta.
* Moved "How can I help?" section in copypasta to just above "contribute" section.
* If the "contribute" section in copypasta is deemed sufficient, I can remove the mostly identical section in non-copypasta.
* Final OP counts: 3851 characters, 33 links