Complete documentation for Notification creation

Notifications support several options that were yet to be documented:
`buttons`, `description`, and `stack`. Add descriptions for each option
and its defaults (where applicable, e.g. .buttons.className).

`stack` is technically available on all notification types, but it
doesn't make sense to use it on types other than 'error' and 'fatal'.
Therefore it's documented only in those two cases.

The usage and expected display, like preformatted vs. Markdown, taken
from [atom/notifications/lib/notification-element.coffee][1].

[1]: https://github.com/atom/notifications/blob/v0.64.1/lib/notification-element.coffee

src/notification-manager.coffee

@@ -33,8 +33,18 @@ class NotificationManager
   #
   # * `message` A {String} message
   # * `options` (optional) An options {Object} with the following keys:
-  #    * `detail` (optional) A {String} with additional details about the
-  #      notification.
+  #    * `buttons` (optional) An {Array} of {Object} where each {Object} has the
+  #      following options:
+  #      * `className` (optional) {String} additional class name add to the
+  #        button. It will already receive `btn btn-success`.
+  #      * `onClick` (optional) {Function} callback to call when the button is
+  #        clicked. The context will be set to the {NotificationElement}
+  #        instance.
+  #      * `text` {String} inner text for the button
+  #    * `description` (optional) A {String} that will be rendered as Markdown
+  #      to describe the notification.
+  #    * `detail` (optional) A preformatted {String} that will be rendered as
+  #      plain text with details about the notification.
   #    * `dismissable` (optional) A {Boolean} indicating whether this
   #      notification can be dismissed by the user. Defaults to `false`.
   #    * `icon` (optional) A {String} name of an icon from Octicons to display
@@ -46,8 +56,18 @@ class NotificationManager
   #
   # * `message` A {String} message
   # * `options` (optional) An options {Object} with the following keys:
-  #    * `detail` (optional) A {String} with additional details about the
-  #      notification.
+  #    * `buttons` (optional) An {Array} of {Object} where each {Object} has the
+  #      following options:
+  #      * `className` (optional) {String} additional class name add to the
+  #        button. It will already receive `btn btn-info`.
+  #      * `onClick` (optional) {Function} callback to call when the button is
+  #        clicked. The context will be set to the {NotificationElement}
+  #        instance.
+  #      * `text` {String} inner text for the button
+  #    * `description` (optional) A {String} that will be rendered as Markdown
+  #      to describe the notification.
+  #    * `detail` (optional) A preformatted {String} that will be rendered as
+  #      plain text with details about the notification.
   #    * `dismissable` (optional) A {Boolean} indicating whether this
   #      notification can be dismissed by the user. Defaults to `false`.
   #    * `icon` (optional) A {String} name of an icon from Octicons to display
@@ -59,8 +79,18 @@ class NotificationManager
   #
   # * `message` A {String} message
   # * `options` (optional) An options {Object} with the following keys:
-  #    * `detail` (optional) A {String} with additional details about the
-  #      notification.
+  #    * `buttons` (optional) An {Array} of {Object} where each {Object} has the
+  #      following options:
+  #      * `className` (optional) {String} additional class name add to the
+  #        button. It will already receive `btn btn-warning`.
+  #      * `onClick` (optional) {Function} callback to call when the button is
+  #        clicked. The context will be set to the {NotificationElement}
+  #        instance.
+  #      * `text` {String} inner text for the button
+  #    * `description` (optional) A {String} that will be rendered as Markdown
+  #      to describe the notification.
+  #    * `detail` (optional) A preformatted {String} that will be rendered as
+  #      plain text with details about the notification.
   #    * `dismissable` (optional) A {Boolean} indicating whether this
   #      notification can be dismissed by the user. Defaults to `false`.
   #    * `icon` (optional) A {String} name of an icon from Octicons to display
@@ -72,12 +102,24 @@ class NotificationManager
   #
   # * `message` A {String} message
   # * `options` (optional) An options {Object} with the following keys:
-  #    * `detail` (optional) A {String} with additional details about the
-  #      notification.
+  #    * `buttons` (optional) An {Array} of {Object} where each {Object} has the
+  #      following options:
+  #      * `className` (optional) {String} additional class name add to the
+  #        button. It will already receive `btn btn-error`.
+  #      * `onClick` (optional) {Function} callback to call when the button is
+  #        clicked. The context will be set to the {NotificationElement}
+  #        instance.
+  #      * `text` {String} inner text for the button
+  #    * `description` (optional) A {String} that will be rendered as Markdown
+  #      to describe the notification.
+  #    * `detail` (optional) A preformatted {String} that will be rendered as
+  #      plain text with details about the notification.
   #    * `dismissable` (optional) A {Boolean} indicating whether this
   #      notification can be dismissed by the user. Defaults to `false`.
   #    * `icon` (optional) A {String} name of an icon from Octicons to display
   #      in the notification header. Defaults to `'flame'`.
+  #    * `stack` (optional) A preformatted {String} with stack trace information
+  #      describing the location of the error.
   addError: (message, options) ->
     @addNotification(new Notification('error', message, options))
 
@@ -85,12 +127,24 @@ class NotificationManager
   #
   # * `message` A {String} message
   # * `options` (optional) An options {Object} with the following keys:
-  #    * `detail` (optional) A {String} with additional details about the
-  #      notification.
+  #    * `buttons` (optional) An {Array} of {Object} where each {Object} has the
+  #      following options:
+  #      * `className` (optional) {String} additional class name add to the
+  #        button. It will already receive `btn btn-error`.
+  #      * `onClick` (optional) {Function} callback to call when the button is
+  #        clicked. The context will be set to the {NotificationElement}
+  #        instance.
+  #      * `text` {String} inner text for the button
+  #    * `description` (optional) A {String} that will be rendered as Markdown
+  #      to describe the notification.
+  #    * `detail` (optional) A preformatted {String} that will be rendered as
+  #      plain text with details about the notification.
   #    * `dismissable` (optional) A {Boolean} indicating whether this
   #      notification can be dismissed by the user. Defaults to `false`.
   #    * `icon` (optional) A {String} name of an icon from Octicons to display
   #      in the notification header. Defaults to `'bug'`.
+  #    * `stack` (optional) A preformatted {String} with stack trace information
+  #      describing the location of the error.
   addFatalError: (message, options) ->
     @addNotification(new Notification('fatal', message, options))