docs: add frontend.hotdeploy.dependencies documentation

Author: tepi

articles/flow/configuration/properties.adoc

@@ -225,6 +225,12 @@ Bundle parameter controls parts of frontend bundle creation.
 |`false`
 |Development
 
+|`frontend.hotdeploy.dependencies`
+|`vaadin.frontend.hotdeploy.dependencies`
+|A comma-separated list of module directories to watch for frontend file changes when detecting hot-deployable changes. Entries need to point to directories relative to the root project, and can point to the root project itself as well, in case it has frontend files as resources. The value could be for example "./,./component-module-1,./component-module-2". Flow will watch for changes in both `src/main/resources/META-INF/frontend` and `src/main/resources/META-INF/resources/frontend` directories under the given entries.
+|``
+|Development
+
 |`heartbeatInterval`
 |`vaadin.heartbeatInterval`
 |Sets the heartbeat interval time. UIs that are open on the client-side send a regular heartbeat to the server indicating that they're still active even without ongoing user interaction. When the server doesn't receive a valid heartbeat from a given UI within a certain amount of time, it removes that UI from the session. The interval value is expressed in `seconds`. See also `closeIdleSessions`.