Update tour to reflect new workflow

Update the builder tour to reflect the new workflow steps and add
a tour step to mention editing the title and byline.

In a departure from the suggested text, at
https://github.com/PitonFoundation/atlas/issues/879#issuecomment-28801093
I chose to mentioning editing the title and byline in a single
tour step and suggested pressing "Enter" to save the changes instead
of "Click anywhere on the screen to save."

Addresses #879