Nitpicky fix on Macports install info (#68)

herbygillot · FiloSottile · commit 5f8e78d01208 · 2018-08-24T21:37:51.000-06:00
diff --git a/README.md b/README.md
@@ -41,11 +41,12 @@ brew install mkcert
 brew install nss # if you use Firefox
 ```
 
-or MacPorts.
+or [MacPorts](https://www.macports.org/).
 
 ```
-sudo port sync
+sudo port selfupdate
 sudo port install mkcert
+sudo port install nss # if you use Firefox
 ```
 
 ### Linux
