Remove webhook endpoint to create tasks (breaking change)

doc/webhooks.markdown

@@ -269,36 +269,3 @@ Screenshot created:
   }
 }
 ```
-
-How to create a task with a web hook?
--------------------------------------
-
-Firstly, you have to get the token from the settings page. After that, just call this url from anywhere:
-
-```bash
-# Create a task for the default project inside the first column
-curl "http://myserver/?controller=webhook&action=task&token=superSecretToken&title=mySuperTask"
-
-# Create a task to another project inside a specific column with the color red
-curl "http://myserver/?controller=webhook&action=task&token=superSecretToken&title=task123&project_id=3&column_id=7&color_id=red"
-```
-
-### Available responses
-
-- When a task is created successfully, Kanboard return the message "OK" in plain text.
-- However if the task creation fail, you will get a "FAILED" message.
-- If the token is wrong, you got a "Not Authorized" message and a HTTP status code 401.
-
-### Available parameters
-
-Base URL: `http://YOUR_SERVER_HOSTNAME/?controller=webhook&action=task`
-
-- `token`: Token displayed on the settings page (required)
-- `title`: Task title (required)
-- `description`: Task description
-- `color_id`: Supported colors are yellow, blue, green, purple, red, orange and gray
-- `project_id`: Project id (Get the id from the project page)
-- `owner_id`: Assignee (Get the user id from the user's page)
-- `column_id`: Column on the board (Get the column id from the projects page, mouse over on the column name)
-
-Only the token and the title parameters are mandatory. The different id can also be found in the database.