Add links to `README.md` file for Who's using it section

CONTRIBUTORS.rst

@@ -553,6 +553,7 @@ Contributors
 * John Simms
 * Justin Michalicek
 * Nabil Khalil
+* Fahim Bin Amin
 
 Translators
 ===========

README.md

@@ -44,7 +44,7 @@ For detailed installation and setup docs, see [docs.wagtail.io](https://docs.wag
 
 ### Who’s using it?
 
-Wagtail is used by NASA, Google, Oxfam, the NHS, Mozilla, MIT, the Red Cross, Salesforce, NBC, BMW, and the US and UK governments. Add your own Wagtail site to [madewithwagtail.org](https://madewithwagtail.org).
+Wagtail is used by [NASA](https://www.nasa.gov/), [Google](https://www.google.com/), [Oxfam](https://www.oxfam.org/en), the [NHS](https://www.nhs.uk/), [Mozilla](https://www.mozilla.org/en-US/), [MIT](https://www.mit.edu/), the [Red Cross](https://www.icrc.org/en), [Salesforce](https://www.salesforce.com/), [NBC](https://www.nbc.com/), [BMW](https://www.bmw.com/en/index.html), and the US and UK governments. Add your own Wagtail site to [madewithwagtail.org](https://madewithwagtail.org).
 
 ### Documentation