Fixed a simple fat-finger typo in the installation instructions.

git-svn-id: https://plugins.svn.wordpress.org/instant-breadcrumbs/trunk@846645 b8457f37-d9ea-0310-8a92-e5e31aec5664
Trying to fix the faq in the readme, because wordpress.org is a bit different to Markdown.

git-svn-id: https://plugins.svn.wordpress.org/instant-breadcrumbs/trunk@846646 b8457f37-d9ea-0310-8a92-e5e31aec5664