Updated docs to describe installation of all required flux components

docs/03-flux.md

@@ -38,6 +38,15 @@ from `docs/01-bootstrap.md` step 4, not SSH (Forgejo's git-SSH port turned
 out not to be reliably reachable from either this desktop or the T630 —
 see the earlier troubleshooting in this project's history):
 
+`flux bootstrap` only installs its four core controllers
+(`source-controller`, `kustomize-controller`, `helm-controller`,
+`notification-controller`) unless told otherwise. hello-app's image
+automation (step 7 below — `ImageRepository`/`ImagePolicy`/
+`ImageUpdateAutomation`) needs two more, `image-reflector-controller` and
+`image-automation-controller`, which are opt-in via `--components-extra`;
+without it, hello-app's `Kustomization` fails dry-run with "no matches for
+kind ImageRepository" since the CRD was never installed.
+
 ```sh
 flux check --pre --kubeconfig ~/.kube/config-manual
 
@@ -48,6 +57,7 @@ flux bootstrap git \
   --username=codegit \
   --password=<FLUX_WRITE_TOKEN> \
   --token-auth \
+  --components-extra=image-reflector-controller,image-automation-controller \
   --kubeconfig ~/.kube/config-manual
 ```
 
@@ -89,7 +99,9 @@ kubectl -n flux-system get deployments
 ```
 
 `source-controller`, `kustomize-controller`, `helm-controller`,
-`notification-controller`. Alongside them, it registered the CRDs those
+`notification-controller`, plus `image-reflector-controller` and
+`image-automation-controller` from `--components-extra` above. Alongside
+them, it registered the CRDs those
 controllers understand:
 
 ```sh