It’s short. The Real-World Guide to Coming Out is a Gay catechism. You have to read it so see what I mean. And at one time, it used to be a free Kindle ebook.
Not as short and focused as the Heidelberg. Not as long-winded as the catechistic portions of the Koran. But it’s still a catechism, and you should read it, especially if you are a Christian minister.