add examples and test VM

examples/bitcoin.nix

@@ -0,0 +1,18 @@
+{ pkgs, ... }:
+{
+  services.panoptikon.enable = true;
+  services.panoptikon.watchers = {
+    bitcoin-price = {
+      script = pkgs.panoptikonWatchers.json {
+        jqScript = ".[]|{name: .name, price: .current_price, change: .price_change_24h}";
+      } "https://api.coingecko.com/api/v3/coins/markets?vs_currency=usd&ids=bitcoin";
+      frequency = "*:0/30";
+      reporters = [
+        (pkgs.panoptikonReporters.telegram {
+          chatId = "123";
+          tokenPath = pkgs.writeText "my-telegram-token.txt" "123:abc";
+        })
+      ];
+    };
+  };
+}