Official development will continue at: https://github.com/swishs-client-mod-plugins/sperm-bank
Alternatively you can use @SammChesse's fork https://github.com/SammCheese/holy-notes but powercord is a sinking ship so have fun while it lasts.
Archived Text Below:
Welcome to the dark side. This is a port of Holy Notes for powercord.
For installation, go to Plugins -> Open a CMD / Powershell / Terminal / Gitbash in the folder, and enter the following:
git clone https://github.com/swishs-client-mod-plugins/holy-notes