feat: implement working reconciliation logic and documentation

initial commit for working reconciliation logic, no automated test only manually tested for now

config/manager/image_pull_secret_patch.yaml

@@ -0,0 +1,10 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: controller-manager
+  namespace: system
+spec:
+  template:
+    spec:
+      imagePullSecrets:
+      - name: ghcr-secret

config/manager/kustomization.yaml

@@ -1,2 +1,11 @@
 resources:
 - manager.yaml
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+images:
+- name: controller
+  newName: ghcr.io/bapung/gitea-runner-operator
+  newTag: sha-b33c78b
+
+patchesStrategicMerge:
+- image_pull_secret_patch.yaml