In the handwriting recognition it is easy to add shortcuts.

I use a long right-hand loop to do "www."
and I use a plus sign with the left spoke connected to the bottom spoke to mean ".com".

I am not aware of any way to put a shortcut on the emulated keyboard screen though.

There are a number of "spare" spots where you could conceivably put them on the symbols portion of the emulated keyboard (2-symbols tab, 5-Accents a-m tab, 10-Accents n-z tab).