update readme with flow and theme manage api (#177)

* update readme with flow and theme manage api

related descope/etc#2417

* update readme type

* fix lint

* update readme comments

Author: Bars92

README.md

@@ -663,6 +663,35 @@ groupsRes.data.forEach((group) => {
 });
 ```
 
+### Manage Flows
+
+You can import and export flows and screens, or the project theme:
+
+```typescript
+// Export the flow and it's matching screens based on the given id
+const res = await descopeClient.management.flow.export('sign-up');
+console.log('found flow', res.data.flow);
+res.data.screens.forEach((screen) => {
+  // do something
+});
+
+// Import the given flow and screens as the given id
+const { flow, screens } = res.data;
+const updatedRes = descopeClient.management.flow.import('sign-up', flow, screens);
+console.log('updated flow', updatedRes.data.flow);
+updatedRes.data.screens.forEach((screen) => {
+  // do something
+});
+
+// Export the current theme of the project
+const res = descopeClient.management.theme.export();
+console.log(res.data.theme);
+
+// Import the given theme to the project
+const updatedRes = descopeClient.management.theme.import(theme);
+console.log(updatedRes.data.theme);
+```
+
 ### Manage JWTs
 
 You can add custom claims to a valid JWT.