Seedling stunted, why?

I think your light is too close. See how short the internodal space is? i think you rleaves are yellowing due to too much light.. slightly too much or it would be worse. but, growth pattern is too tight, so raise those lights.. don't feed as soil likely is good to go this early on its own and you'll only make it worse. I see three nodes on top of each other and paling leaves... 95% certain it is light caused.. i usually beat around the bush more and not so confident, but this is safe. (these things are tough to deduce without all information, and impossible to expect such a thing to be given)