README: Added link to blog post

Added a link to the Medium post with the full project write-up.

README.md

@@ -5,11 +5,9 @@ quartz clock with self-dimming LED display.
 
 ![](clock1.jpg)
 
+Full write-up is at https://medium.com/@erikvanzijst/a-digital-quartz-clock-from-scratch-a80ec5e427
+
 ## Kicad symbol and footprint libraries
 The project uses the [DigiKey Kicad symbol and footprint libraries](https://github.com/Digi-Key/digikey-kicad-library).
 After cloning or downloading those locally, [add them to the Kicad Symbol and
 Footprint libraries](https://forum.digikey.com/t/importing-the-digi-key-kicad-library-into-kicad-5-0-0/4075).
-
-
-
-https://www.eevblog.com/forum/beginners/using-a-32-768khz-crystal-with-4060-frequency-divider/