Merge pull request #787 from snyk/docs/add_reuse_values

docs: add info on --reuse-values to README

Author: KatieArmstr

snyk-monitor/README.md

@@ -188,12 +188,19 @@ By default, `snyk-monitor` does not scan containers that are internal to Kuberne
 * `kube-system`
 * `local-path-storage`
 
-If you prefer to override this, you can add your own list of namespaces to exclude by setting the `excludedNamespaces` to your own list.
-For example:
+If you prefer to override this, you can add your own list of namespaces to exclude by setting the `excludedNamespaces` to your own list. For example:
 ```yaml
 --set excludedNamespaces={kube-node-lease,kube-public,local-path-storage,some_namespace}
 ```
 
+## Upgrading
+
+When upgrading the Snyk monitor, if you would like to reuse the last release's values and merge in any overrides from the command line via --set and -f, you can use the option `--reuse-values`. For example:
+```bash
+helm upgrade snyk-monitor snyk-charts/snyk-monitor --reuse-values
+```
+If '--reset-values' is specified, this is ignored.
+
 ## Terms and conditions ##
 
 *The Snyk Container Kubernetes integration uses Red Hat UBI (Universal Base Image).*