An experiment: Find a schoolteacher (K-12, pre-K, community college...) and ask him or her to look at the front-page. What initial impression is given off by the page? If this seems like it could potentially be a good place to ask a question, then is it clear how to proceed? (What else might you ask him or her?)
If I am a first grade teacher who has to align my lessons with the (U.S.) Common Core State Standards for Mathematics (CCSSM), and I already feel a bit out of my element with regard to mathematical content, then I imagine that opening the site and seeing Can GAP/Magma be helpful for a first abstract algebra course? or Computational topology for engineers would be a bit overwhelming.
I'd probably think I am in the wrong place.
This is not to say that these questions are bad; in fact, I think each is well-posed (and, incidentally, I think Alexander Gruber's answers to both are quite nice).
But here are two suggestions on how to make schoolteachers feel more welcome:
Include a side-bar with sample questions at different levels. For example, have recent questions (or highly voted ones, or randomly generated ones, or...) with, at least, primary-education, secondary-education, undergraduate-education, and graduate-education listed. That way, even if the main body has questions about abstract algebra or topology, I can still look for the level at which I'm more comfortable and at which my own potential question might fit in.
Include a guide of the form: I'm wondering about something related to mathematics education (teaching, learning, etc) at some level. How do I turn this into an appropriate question? Then have this link to a page that begins with a general experience or idea ("Mathematical modeling" is now a standard for mathematical practice in CCSSM and is supposed to be covered in secondary school; but I've never studied modeling and don't know how to teach it!) and guides the user through how this could be turned into a well-formulated question. (Background, what has been tried already, what exactly the user is looking/hoping for, how to combine this into a question, how to title the question, how to tag the question, etc). Then conclude by showing what it would look like in its full version.
It might even be a good idea to carry out suggestion two at different levels (maybe this can be done at the extremes: one at Pre-K and another at the graduate level). Probably there should be some mention elsewhere about the other types of questions that are welcome here, e.g., historical ones about mathematics education (Edit: depending on its nature, a historical question might fit better at another SE site that has since emerged, HSM), but I think this post of mine is already sufficiently prolix...