Add custom integration branding icon

[RoboMagus]

Since 2026.3 custom integrations can now ship their own icon / logo without the need to push that to the HA branding repository.

It'd be nice to have this integration feature the PostNL logo so it can be found more easily visually on e.g. the integration page.

Just add an icon in custom_components/postnl/brand/icon.png and HA picks it up from there.

I'd create a PR for this myself, but since choosing a logo is a matter of taste I believe it's best to leave that choice up to the maintainer.

[peternijssen]

Missed that you also had a PR in place if needed. Just wanted to make sure that there was a logo. Feel free to submit your PR and I will remove mine.

[RoboMagus]

I had not yet made a PR for this myself, but looking at #46 thats pretty much what I would do.

In the mean time I dropped this image into the required location of the custom_components directory:

(I don't believe that logo is the most up to date one, it's just the first I could find that has a transparent background such that the whole thing does not stick out too much on the integrations dashboard)