ShortURL config for mediawiki AWS instance

I am struggling to configure ShortURL for my Bitnami mediawiki AWS instance. I would like to configure the URL from BASEURL/mediawiki/index.php/Main_Page to BASEURL/mediawiki/Main_Page but am failing to get the rewrites working.

Changes so far have been,

1. mediawiki.conf - uncommented pre-existing RewriteEngine & RewriteRule lines. Also added lines RewriteRule ^/?mediawiki(/.*)?$ %{DOCUMENT_ROOT}/mediawiki/index.php [L] & RewriteRule ^/*$ %{DOCUMENT_ROOT}/mediawiki/index.php [L]

2. LocalSettings.php - have added lines $wgArticlePath = "/mediawiki/$1"; & $wgUsePathInfo = true;

But always get a page not found error. Off point is error message says URL /mediawiki.png/index.php not found. Why is it referencing mediawiki.png??

Any assistance would be much appreciated.