Generating API documention

[George]

What do people use to generate nice looking and simple html 
documentation for their projects? I would be glad (and if 
possible), someone could share some actual instructions rather 
than just tell me ddoc. For example I have seen the libmir 
(http://docs.mir.dlang.io/latest/index.html) and I would love to 
generate something similar for a project I am working on.

Thank you and best wishes.
George