fine-tune 2 default settings

[whatacold]

Hey TEC,

Here are 2 default setting improvements that I think would make sense:

1. Also clean up trailing whitespaces for converted markdown contents.
2. With (add-to-list 'default-frame-alist '(fullscreen . maximized))
   for Emacs on GNOME, the newly created EE frame will also be
   maximized without (fullscreen . nil). It works after adding it
   (although the height is not what I specify, the result is better),
   and I think it makes sense to add this property in the parameters.

[tecosaur]

Those do seem nicer, thanks for the PR!