Also, reading the mod_access documentation of the "Redirect" directive will soon reveal that
redirect 301 http://www.example.com/ http://www.example.com/intro
won't redirect anything, since the Redirect directive looks only at the URL-path-prefix. In this case, the URL-path should have been specified as
Redirect 301 / http://www.example.com/intro
But that would redirect all URLs in this domain after prepending ("intro"), and then redirect that page URL to add intro again and again -- looping forever. This is because the Redirect directive uses prefix-matching -- anything that starts with the specified URL-path is redirected to the new URL, with any part of the requested URL-path not specified in the Redirect directive appended to the new URL.
So, the path forward is to use RewriteRule instead of Redirect, and to put the rules in order: External redirects first, in order from most-specific URL-path and conditions to least, followed by all internal rewrites, again in order from most-specific to least. In this particular case, your WP code will go last.
Jim