In the Chrome address bar (or Omnibox as Google calls it)
- At the top right click the three dots and then settings
- Under "Search engine," click manage search engines
- Select the triangle where it says "Other search engines."
- Select add "on same line as "Other search engines."
- Name the search engine - example Facebook
- Enter in a keyword - For Facebook - maybe just Face
- Under where it has URL make sure to do the following
- Enter in the website address with this after it (search?q=%s)
- Example - https://www.facebook.com/search?q=%s
- Select add
- When in your Omnibox / address bar type in your keyword and then Tab you can now search the site
Embedded below is a GIF followed by a 1 minute 24 second YouTube tutorial I created.