Index file priority list [mediawiki]

Hi everyone,

Just a quick backstory, I have to maintain a mediawiki installation on a server already running NGinx. I had no prior experience with it, hence I have no idea who install it on our server and how it works.

Now for the situation: I had a mediawiki installation running perfectly fine. However one of the requests I got was to design a front page for it (similar to wikipedia) - just the logo of the company and a search field. Just a static html file. I placed it at the root folder of said mediawiki installation and while it was working perfectly on my local machine (Apache), when I uploaded to our server (NGinx) the domain was pointing to the index.php. I placed the .htaccess prioritizing index.html on top of index.php but it didn't work.

I searched quite extensively and I found this page here (http://nginx.org/en/docs/http/ngx_http_index_module.html#example) that points to a "ngx_http_index_module". So tweaking the example a little bit I assume this would work:
location / {
index index.html index.php;
}

However, I have no idea where to put this piece of code. That's why I am here, you guys have the experience. Any help will be appreciate.