Try to add some meat to the on topic page. Also, in the about page, you can edit the site target audience, the example question, and the bullet points that define what to ask about/what not to ask about.
You may want to create a draft as an answer here and collaboratively work on it; that's how new sites usually do it.
These are all moderator-editable. I suggest you look at the corresponding pages on MSE for ideas.