Remove the documentation for the <s-g> keybinding

It was removed in commit d49a8e9a16 and it
is now bound to the god-local-mode command.

README.md

@@ -309,6 +309,7 @@ Keybinding         | Description
 <kbd>C-c . #</kbd> | Convert integer at point to specified base. Default is 10.
 <kbd>C-c . %</kbd> | Replace integer at point with another specified integer.
 <kbd>C-c . '</kbd> | Perform arithmetic operations on integer at point. User specifies the operator.
+<kbd>Super-g</kbd> | Toggle between God mode and non-God mode
 <kbd>Super-r</kbd> | Recent files
 <kbd>Super-j</kbd> | Join lines
 <kbd>Super-k</kbd> | Kill whole line

core/prelude-core.el

@@ -380,7 +380,7 @@ Doesn't mess with special buffers."
 (defvar prelude-tips
   '("Press <C-c o> to open a file with external program."
     "Press <C-c p f> or <s-f> to navigate a project's files with ido."
-    "Press <C-c p g> or <s-g> to run grep on a project."
+    "Press <C-c p g> to run grep on a project."
     "Press <C-c p s> or <s-p> to switch between projects."
     "Press <C-=> to expand the selected region."
     "Press <C-c g> to search in Google."