Firstly for a URL link to be created for each document – the document must be saved inside the File Repository - you can save inside a folder but our advice would be not to save inside sub folders. 

You can create URL links for:

PDF documents

Word documents

Excel documents 

Images such as JPEG and PNG files

Part of the solution is done using the instructions contained in this link to create a URL link for each document:

Once a URL link is created this can be stored on an Excel file – which is then stored on the Files system (inside a folder) – allowing team members to access the documents via the spreadsheet using the URL link relating to each document instead of accessing the master copy.