Update opening-modals.md (removed extra s) (#1161)

All I did was remove an 's' after the "Modals
 link that seems like it isn't supposed to be there.

Author: Rat-Fiend

docs/content/basic/opening-modals.md

@@ -4,7 +4,7 @@ lang: en
 slug: /concepts/opening-modals
 ---
 
-[Modals](https://api.slack.com/block-kit/surfaces/modal)s are focused surfaces that allow you to collect user data and display dynamic information. You can open a modal by passing a valid `trigger_id` and a [view payload](https://api.slack.com/reference/block-kit/views) to the built-in client's [`views.open`](https://api.slack.com/methods/views.open) method.
+[Modals](https://api.slack.com/block-kit/surfaces/modal) are focused surfaces that allow you to collect user data and display dynamic information. You can open a modal by passing a valid `trigger_id` and a [view payload](https://api.slack.com/reference/block-kit/views) to the built-in client's [`views.open`](https://api.slack.com/methods/views.open) method.
 
 Your app receives `trigger_id`s in payloads sent to your Request URL that are triggered by user invocations, like a shortcut, button press, or interaction with a select menu.
 
@@ -52,4 +52,4 @@ def open_modal(ack, body, client):
             ]
         }
     )
-```
+```