doc: git-worktree: Link to examples

Also add advice to put new worktrees outside of existing ones.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: hramrach

Documentation/git-worktree.adoc

@@ -79,6 +79,9 @@ with a matching name, treat as equivalent to:
 $ git worktree add --track -b <branch> <path> <remote>/<branch>
 ------------
 +
+For best results it is advised to specify _<path>_ outside of the repository
+and existing worktrees - see <<EXAMPLES,EXAMPLES>>
++
 If the branch exists in multiple remotes and one of them is named by
 the `checkout.defaultRemote` configuration variable, we'll use that
 one for the purposes of disambiguation, even if the `<branch>` isn't
@@ -498,6 +501,7 @@ locked "reason\nwhy is locked"
 ...
 ------------
 
+[[EXAMPLES]]
 EXAMPLES
 --------
 You are in the middle of a refactoring session and your boss comes in and