add poll docs

Author: Birdie0

docs/SUMMARY.md

@@ -20,6 +20,7 @@
   * [thumbnail](structure/embed/thumbnail.md)
   * [footer](structure/embed/footer.md)
   * [timestamp](structure/embed/timestamp.md)
+* [poll](structure/poll.md)
 * [tts](structure/tts.md)
 * [allowed_mentions](structure/allowed_mentions.md)
 * [file](structure/file.md)

docs/discord_webhook.md

@@ -1,6 +1,6 @@
 # Structure of Webhook
 
-Before using Webhooks you have to know the structure. All elements listed here are *optional* but request body should contain `content`, `embeds` or attachments, otherwise request will fail.
+Before using Webhooks you have to know the structure. All elements listed here are *optional* but request body should contain `content`, `embeds`, `poll` or attachments, otherwise request will fail.
 
 * `username` - overrides the predefined username of the webhook
 * `avatar_url` - overrides the predefined avatar of the webhook
@@ -26,6 +26,17 @@ Before using Webhooks you have to know the structure. All elements listed here a
     * `text` - footer text, doesn't support Markdown
     * `icon_url` - url of footer icon
   * `timestamp` - ISO8601 timestamp (`yyyy-mm-ddThh:mm:ss.msZ`)
+* `poll` - poll object
+  * `question` - poll question object
+    * `text` - poll question text
+  * `answers` - array of poll answer objects
+    * `poll_media` - poll answer object
+      * `text` - poll answer text
+      * `emoji` - emoji object (optional)
+        * `id` - id of emoji (if custom)
+        * `name` - name of emoji (if built-in)
+  * `duration` - duration of the poll in hours
+  * `allow_multiselect` - if true, allows to select multiple answers
 * `tts` - makes message to be spoken as with `/tts` command
 * `allowed_mentions` - object allowing to control who will be mentioned by message
   * `parse` - array, can include next values: `"roles"`, `"users"` and `"everyone"`, depends on which decides which mentions work. If empty, none mention work.

docs/img/structure/poll.png

@@ -0,0 +1,57 @@
+# poll
+
+Allows to add poll to message. Poll always has a question (up to 300 characters) with at least 1 answer (up to 10 options total, up to 55 characters per each). Poll duration can be set to value between 1 and 768 hours (32 days), if omitted 24 hours are assumed. Additionally, multiple answers mode is available, but there's no way to limit how many can be selected at time when it's enabled.
+
+Structure can be a bit confusing at first, let's break it down:
+
+* `poll` - poll object
+  * `question` - poll question object
+    * `text` - poll question text value, up to 300 characters
+  * `answers` - array of poll answer objects, up to 10 options can be specified, at least 1 is required
+    * `poll_media` - poll answer object
+      * `text` - poll answer text
+      * `emoji` - emoji object, optional
+        * `id` - id of emoji, should be provided as string, used when emoji is custom
+        * `name` - name of emoji, should be written as Unicode character, used when emoji is built-in
+  * `duration` - duration of the poll in hours (1-768), default is 24 hours
+  * `allow_multiselect` - if true, allows to select multiple answers, optional, default is false
+
+Example:
+
+```json
+{
+  "poll": {
+    "question": {
+      "text": "Cat person or dog person?"
+    },
+    "answers": [
+      {
+        "poll_media": {
+          "text": "meow!",
+          "emoji": {
+            "name": "🐱"
+          }
+        }
+      },
+            {
+        "poll_media": {
+          "text": "woof!",
+          "emoji": {
+            "name": "🐶"
+          }
+        }
+      }
+    ],
+    "allow_multiselect": true,
+    "duration": 48
+  }
+}
+```
+
+![poll example](../img/structure/poll.png)
+
+## Additional information
+
+By adding `wait=true` to the request query, you can get a response with the message structure, that will include all kind of data about message, including Message ID. Later on it can be used to get poll results using [Get Webhook Message](https://discord.com/developers/docs/resources/webhook#get-webhook-message) request, it allows to see number of votes, but not voters. Additionally there's no way to close poll as it's possible for users and bots (both can only close own polls only).
+
+[Discord API reference](https://discord.com/developers/docs/resources/poll#poll-create-request-object)