How to sign up, urlStarterFeeds setting

Read docs/signup.md for the documented account setup flow and inspect config.json for the urlStarterFeeds setting. Confirm that the setup instructions cover account creation as the final step and explain how a custom OPML starter-feed URL is configured; the issue does not identify a specific missing edit or test.

Two updates this morning.

1. A new docs page explaining how to sign up for a new account on your instance, using the FeedLand software. This should be the last step in the setup process, and now it's documented that way. After having gone through all the steps, to really get underway with testing you must have an account. Also this is the first time this new interface has appeared, identity on feedland.org is done through Twitter. This is the user interface for the new system where the user provides a unique name and email address, and we don't involve another service.

2. The urlStarterFeeds setting in config.json, if specified is the URL of your default subscription list. The last step in creating a new user is to offer to add a few feeds to get started. That feature just reads an OPML subscription list and then subscribes to each of the feeds in the list. I provide a default list but you may want to provide your own default list for your users. For example, if you were running a FeedLand instance for a department in a medical school, you'd want to provide a set of feeds about medical research, focused on the interests of your users.

Once a few of you get your setups working and we've established a set of steps to test your instance (still to come), we'll want to invite some FeedLand users to come try out your instances, to see how they work for users. I'd like to limit that at first to people who currently use FeedLand. So think about whether you'd like to participate in this, the question will come up probably in a few days.

Also we will be working, together, to be sure this software can run behind an HTTPS server.