Add maximum length for a button URL (#7301)

Co-authored-by: advaith <[email protected]>

Author: Yareaj

docs/components/reference.mdx

@@ -146,7 +146,7 @@ Buttons must be placed inside an [Action Row](/docs/components/reference#action-
 | emoji?    | partial [emoji](/docs/resources/emoji#emoji-object) | `name`, `id`, and `animated`                                                                                        |
 | custom_id | string                                              | Developer-defined identifier for the button; max 100 characters                                                     |
 | sku_id?   | snowflake                                           | Identifier for a purchasable [SKU](/docs/resources/sku#sku-object), only available when using premium-style buttons |
-| url?      | string                                              | URL for link-style buttons                                                                                          |
+| url?      | string                                              | URL for link-style buttons; max 512 characters                                                                      |
 | disabled? | boolean                                             | Whether the button is disabled (defaults to `false`)                                                                |
 
 Buttons come in various styles to convey different types of actions. These styles also define what fields are valid for a button.