Updated Compile and install on macOS using macports (markdown)

Compile-and-install-on-macOS-using-macports.md

@@ -21,10 +21,7 @@ Install create-dmg:
 
     git clone https://github.com/create-dmg/create-dmg
     cd create-dmg
-    chmod u+x create-dmg
-    sudo cp create-dmg /opt/local/bin/
-    sudo mkdir -p /opt/local/share/create-dmg
-    sudo cp -r support /opt/local/share/create-dmg/
+    sudo make install
 
 Set environment variables: