This template is made so that you can easily fork it to start a new Godot project. That project description would go here.
The main branch is still tracking v3.5.x since it is still the recommended version for HTML 5 exports. I believe the default engine is GLES 2.0 as well
Note that there are branches in this template called opengl-es3, and opengl-es2 in case you want to target a specific one.
I will also be adding v4.x branches very soon now too since they are starting to merge v4 into main.