Srid’s Nix cache

I provide a Nix cache for my open source projects. Add the following cache using these instructions:

Name	Value
substituters	`https://cache.srid.ca`
trusted-public-keys	`cache.srid.ca:8sQkbPrOIoXktIwI0OucQBXod2e9fDjjoEZWn8OXbdo=`