Add example for command n,g,p and grid, update date now examples (#4622)

docs/commands/g.md

@@ -13,3 +13,15 @@ Switch to a given shell.
 ## Parameters
 
  -  `shell_number`: shell number to change to
+
+## Examples
+
+Make two directories and enter new shells for them, use `g` to jump to the specific shell
+```shell
+> mkdir foo bar; enter foo; enter ../bar; g 1
+```
+
+Use `shells` to show all the opened shells and run `g 2` to jump to the third one
+```shell
+> shells; g 2
+```