add examples to docs site

docs/content/examples/pod/default.nix

@@ -0,0 +1,12 @@
+# let's creata a function whose only input is the kubenix package
+{kubenix ? import ../../../..}:
+# evalModules is our main entrypoint
+kubenix.evalModules.${builtins.currentSystem} {
+  # to it, we pass a module that accepts a (different) kubenix object
+  module = {kubenix, ...}: {
+    # in order to define options, we need to import their definitions
+    imports = with kubenix.modules; [k8s];
+    # now we have full access to define Kubernetes resources
+    kubernetes.resources.pods.example.spec.containers.ex.image = "nginx";
+  };
+}