[Marketing] Gimp article update

[Sylvia Sánchez]

Hi everybody!

I added some more stuff to the article.  I tried to upload screenshots
but I couldn't, it gave me a  HTTP error.  Anyone know what does it
means?
In the installation chapter, I'd like to do it a bit more general
instead of pointing specifically to the Gnome version and mention the
Design Spin.  Also I thought of adding the advise  "Do a  dnf search
gimp"  so a new user can install everything related to Gimp.
Otherwise, it will be needed to explain under every item how to
install them because most of Gimp parts are modules coming separated
from the main programme.  I don't want to mess anyone's work but I
think it would be really useful to someone who never worked with Gimp
or even never worked with a design tool at all.
If everything is ok with my suggestions I'll add them and then write a
note with useful links like forums, brushes, etc.


Cheers,
Sylvia