PIMacs/theme Doom Module

Slight customization of the Emacs theme depending the module options used.

Use TerminessTTF Nerd Font by default (use option +no-font to disable this feature).
(Re)Define some faces, trailing-whitespace for example (use option +no-whitespace-style to disable this feature).
Load a slightly customized Zenburn Theme (use option +no-zenburn-theme to disable this feature).
Disable hl-line in non special modes.
Remove line numbering because we have this information into the mode-line.

Module options are :

+no-font : do not modify the default font.
+no-zenburn-theme : do not use Zenburn Theme.
+no-whitespace-style : do not modify the default whitespace style.