Search Function that reads the text on a page as well as the title of the page

Hello, 

We have built a collection of workplace documents for one of our Corporate clients which employees can access and download. Each document is on its own page with the document contents typed out as well as downloadable as a pdf. 

As you might imagine, this list of documents is incredibly difficult to navigate, especialy when the user does not know the name of each document, which is why we would like to add a search bar which would pull up all pages which contain the searched term. 

The built-in search bar only searches by page title, is there a plugin or another work around for this? 

We have tried grouping things into categories but the inventory is just far too large and documents can apply to multiple categories.

Any help is greatly appreciated, thank you.