docs: update appinfo for webhook_listeners app

[pReya]

Summary

I found this app in my Nextcloud and it was very annoying that the App description was so short/non existent. The language around "webhooks" can be very ambiguous (e.g. there are incoming and outgoing webhooks, and the term "listener" can also be misjudged as "listening for incoming webhook").

So I was very confused by the short description of this App. Therefore I looked at the code and created a more detailed App description that might help some people understand easier what this app can be used for.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[come-nc]

Hey.

I get that you were annoyed but the name&shame on Mastodon is really not cool.

For context, this application was developped mainly as a dependency for https://github.com/nextcloud/flow

[come-nc]

This is weirdly technical. But this app kind of is, so I’m unsure.

[come-nc]

Suggested change

<description># Description\nThis is an official Nextcloud app, which enables your Nextcloud to call webhooks, when certain Nextcloud events happen. This app does not have any (visible) user interface or settings. To configure your webhooks, you must use the [Rest API](https://docs.nextcloud.com/server/latest/developer_manual/_static/openapi.html#/operations/webhook_listeners-webhooks-create).</description>

<description>This app enables your Nextcloud to call webhooks, when certain events happen. This app does not have any (visible) user interface or settings. To configure your webhooks, you must use the [Rest API](https://docs.nextcloud.com/server/latest/developer_manual/_static/openapi.html#/operations/webhook_listeners-webhooks-create).</description>

No need for a "description" header in the description.
Regarding "This is an official Nextcloud app", if I remember correctly we do not have such a notion. Some apps are maitaineds by us, some are not, but I do not think we want to put such a strong statement in a description. @jancborchardt might now?

[pReya]

Sorry @come-nc if my comment offended you. I've edited the toot and dialed it down. I did not want to name/shame individual developers or you. My criticism was supposed to go against Nextcloud in general and the priorities and processes within the project.

Thanks for giving the additional information about the reason why this app exists. I think this should also be part of the app description to explain, why a user might find this app in their Nextcloud (maybe because they're also using the Flow app).