corrected link for info about spikes: www.lagerweij.com/2013/04/12/spikes-theyre-sharp/

I redirected lagerweij link to the correct page:
* [http://www.lagerweij.com/2013/04/12/spikes-theyre-sharp/](http://lagerweij.com/2013/04/12/spikes-theyre-sharp/){:target="_blank"}