Discord: Support for "Announcement Channel"

[whallin]

🔖 Feature description

Postiz should support the "Announcement" type of text channel for Discord through Postiz.

🎤 Why is this feature needed ?

Currently, all text channel types in Discord are displayed when creating a post, except for "Announcement" text channels. Given the nature of the "Announcement" text channel type in Discord, it would be expected to be supported by Postiz.

✌️ How do you aim to achieve this?

When selecting a channel for the created post in Postiz, text channels of the "Announcement" type should appear just like all other channels.

🔄️ Additional Information

It may be intended behaviour for the "Announcement" text channel type not to appear among the text channels, but I couldn't find any issues or documentation indicating that this is intentional.

Initially, I thought it might have been a permissions issue within Discord. However, when I disabled the "Announcement Channel" setting on one of these announcement text channels, it appeared immediately in Postiz—so it's not a permissions issue.

I was surprised that "Announcement" text channels don't show. The text channel designated as the community's "Rules or Guidelines Channel" in the server's community overview settings does appear. Even "Forum" text channels show up, and they have a completely different way of interacting with them than regular text channels!

👀 Have you spent some time to check if this feature request has been raised before?

• I checked and didn't find similar issue

Are you willing to submit PR?

None