Removed broken link (#1678)

README.md

@@ -58,7 +58,6 @@ To load the source project you will need Visual Studio 2019. Don't worry if you
 - Logo courtesy of GitHub user [Snalty](https://github.com/snalty), and you can see more of him;
 - on his [blog](http://holothere.tumblr.com/)
 - and on [Twitter](https://twitter.com/snalty)
-- Marc Angers - I pulled some of his shadows straight in from this [blog post](http://marcangers.com/material-design-shadows-in-wpf/)
 - Icon pack sourced from [Material Design Icons](https://materialdesignicons.com/)
 - Utilises [ControlzEx](https://github.com/ControlzEx/ControlzEx)
 - Ignace Maes, whose [Material Skin](https://github.com/IgnaceMaes/MaterialSkin) project inspired the original material design theme for [Dragablz](https://github.com/ButchersBoy/Dragablz), which in turn led to me starting this project