i3,picom: Deactivate gaps and rounded corners

While installing i3 (not i3-gaps, as not easily available) on an Ubuntu
system with my dotfiles, I had to deactivate the gaps.

I think I prefer this look now, as it gives more screen real estate and
looks cleaner in my opinion.

Also deactivate rounded corners through picom as they only really make
sense with gaps enabled.

.config/i3/config

@@ -18,8 +18,8 @@ set $TERMINAL st
 
 # Gaps #########################################################################
 
-gaps inner 10
-gaps outer 7
+# gaps inner 10
+# gaps outer 7
 
 # Execs ########################################################################