mergePatchUpdater is not a thing
I think it's a leftover from old documentation
Also, clarify and rephrase how `patchUpdater` works
@@ -204,8 +204,9 @@ patchUpdated:
patchFile: flux-patch.yaml
```
-The `mergePatchUpdater` will store the modifications made by Flux in file `flux-patch.yaml` and will apply the patch to
-the output of `helm template ../charts/mychart -f overrides.yaml`.
+This configuration will cause:
+1. modifications made by Flux (e.g. due to annotation or image updates) to the resources generated by `helm template ../charts/mychart -f overrides.yaml` to be stored into patch file `flux-patch.yaml`. `flux-patch.yaml` will be managed automatically by Flux (it will be added and updated on demand).
+2. the patch file `flux-patch.yaml` to be always applied to the output of `helm template ../charts/mychart -f overrides.yaml`, in order to obtain the final manifests.
The patch file path should be relative to Flux target which matched the configuration file.
