Add webhook page to docs

[hsluoyz]

See: https://door.casdoor.com/webhooks

[casbin-bot]

@ErikQQY

[Jenniline]

Hi @hsluoyz
I am interested in working on this issue.

I see that this issue requires that one should know how to create a webhook and perform other actions to it. Which I will experiment on using my local setup.

I just have a few questions about this task. I have visited this page https://door.casdoor.com/webhooks
and what I will like to know is,

1. Which part of the casdoor documentation should I add the webhooks documentation to?
   Should I create a directory for the webhooks inside the documentation, then in there I include the overview.md, and the other relevant pages?

I know I should document the process of creating a webhook and other actions relating to the webhooks.
2. Is there anything I should particularly take into consideration?

Thanks

[hsluoyz]

@Jenniline similar answer as: #154 (comment)

[Jenniline]

Noted. with Thanks
I am on it

[hsluoyz]

@Jenniline plz only work on one issue, we don't need to repeat the same words in two issues

[Jenniline]

okay noted
Thanks

[Jenniline]

[Comment Updated]
Hi, @hsluoyz I am currently working on this issue, but I am a bit confused on the part about how Casdoor uses webhooks.
I have the casdoor project running locally and the casdoor-website running locally. That is what I am using to test the documentation I am working on.

Please can you help me with links that will aid me in better understanding how casdoor uses webhooks?
I have been searching but my search has not been fruitful.

Thanks

[hsluoyz]

@Jenniline you need to read Casdoor source code, not Casbin

[Jenniline]

@hsluoyz Thank you for your reply.
I have made a PR for this issue here

Please review and let me know if there are any corrections I should make