Write a chapter on converting users into contributors

[semioticrobotic]

Write a guidebook chapter on best practices for converting project users into project contributors.

While this has been on the outline for some time, I cannot find the appropriate issue linked to it (hence creating this one).

I would like to nominate @dneary as author here, because a great deal of his material already forms the crucible of this chapter (especially if we merge #94).

[quaid]

Dave is writing a conclusion for this chapter using the method/style in #160

When that conclusion is reviewed and copyedited, this issue is complete.