Feature request: entity whitelist (inverse of ignore rule)

[danielrosehill]

I'm configuring Watchman to notify of unavailable lights (specifically).

Currently the only way for me to achieve this is to:

1: Run an offline entities report 2: Add all the notification groups I don't want to hear about by adding them as ignore options (scene., sensor. etc).

It would be great if there were the inverse option of ignore -- a whitelist (only report on entities matching these conditions).

Then I could just add: light.* to achieve the same functionality.