feat(kustomize): update kustomize docs

Signed-off-by: arlan lloyd <arlanlloyd@gmail.com>

docs/user-guide/kustomize.md

@@ -12,12 +12,64 @@ The following configuration options are available for Kustomize:
 * `namespace` is a kubernetes resources namespace
 * `forceCommonAnnotations` is a boolean value which defines if it's allowed to override existing annotations
 * `commonAnnotationsEnvsubst` is a boolean value which enables env variables substition in annotation  values
+* `patches` is a list of Kustomize patches that supports inline updates
 
 To use Kustomize with an overlay, point your path to the overlay.
 
 !!! tip
     If you're generating resources, you should read up how to ignore those generated resources using the [`IgnoreExtraneous` compare option](compare-options.md).
 
+## Patches
+Patches are a way to kustomize resources using inline configurations in ArgoCD applications.  This allows for kustomizing without  kustomization file.  `patches`  follow the same logic as the corresponding Kustomization.  Any patches that target existing Kustomization file will be merged.
+
+The following Kustomization manifest can be used as example.
+```yaml
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+metadata:
+  name: kustomize-inline-example
+namespace: test1
+resources:
+  - https://raw.githubusercontent.com/argoproj/argocd-example-apps/master/guestbook/guestbook-ui-deployment.yaml
+  - https://raw.githubusercontent.com/argoproj/argocd-example-apps/master/guestbook/guestbook-ui-svc.yaml
+patches:
+  - target:
+      kind: Deployment
+      name: guestbook-ui
+    patch: |-
+      - op: replace
+        path: /spec/template/spec/containers/0/ports/0/containerPort
+        value: 443
+```
+The following is similar and clone the repository, use the specified path, then kustomize.
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: kustomize-inline-guestbook
+  namespace: argocd
+  finalizers:
+    - resources-finalizer.argocd.argoproj.io
+spec:
+  destination:
+    namespace: test1
+    server: https://kubernetes.default.svc
+  project: default
+  source:
+    path: guestbook
+    repoURL: https://github.com/argoproj/argocd-example-apps.git
+    targetRevision: master
+    kustomize:
+      patches:
+        - target:
+            kind: Deployment
+            name: guestbook-ui
+          patch: |-
+            - op: replace
+              path: /spec/template/spec/containers/0/ports/0/containerPort
+              value: 443
+```
+
 ## Private Remote Bases
 
 If you have remote bases that are either (a) HTTPS and need username/password (b) SSH and need SSH private key, then they'll inherit that from the app's repo.