Fixes missing source link on description Progress towards #125.

trackers/advertising.com/index.md

 # Advertising.com by AOL (advertising.com)
 
-> “Advertising.com is an online advertising company based in the United States… It was acquired by AOL [in] 2004.” – [Source](link)
+> “Advertising.com is an online advertising company based in the United States… It was acquired by AOL [in] 2004.” – [Source](https://en.wikipedia.org/wiki/Advertising.com)
 
 ## Ethical design violations