Add request to hide autoplaying gifs in details (#1998)

* Add recommendation to wrap animated gifs in PRs and issues in a details container with a summary
* Update UNRELEASED.md

.github/ISSUE_TEMPLATE/ISSUE.md

@@ -26,6 +26,14 @@ What do you think should happen?
 What actually happens?
 
 Tip: include an error message (in a `<details></details>` tag) if your issue is related to an error while running Polaris.
+
+If you include an animated gif showing your issue, wrapping it in a details tag is also recommended. Gifs usually autoplay, which can cause accessibility issues for people reviewing your PR:
+
+    <details>
+      <summary>Summary of your gif(s)</summary>
+      <img src="..." alt="Description of what the gif shows">
+    </details>
+
 -->
 
 

.github/PULL_REQUEST_TEMPLATE.md

@@ -18,7 +18,15 @@ Fixes #0000 <!-- link to issue if one exists -->
 
 <!--
   Summary of the changes committed.
-  Before / after screenshots appreciated for UI changes.
+
+  Before / after screenshots are appreciated for UI changes. Make sure to include alt text that describes the screenshot.
+
+  If you include an animated gif showing your change, wrapping it in a details tag is recommended. Gifs usually autoplay, which can cause accessibility issues for people reviewing your PR:
+
+    <details>
+      <summary>Summary of your gif(s)</summary>
+      <img src="..." alt="Description of what the gif shows">
+    </details>
 -->
 
 ## <!-- ℹ️ Delete the following for small / trivial changes -->

UNRELEASED.md

@@ -62,6 +62,7 @@ Use [the changelog guidelines](https://git.io/polaris-changelog-guidelines) to f
 - Removed `FilterControl` documentation and case studies from `ResourceList` documentation ([#1774](https://github.com/Shopify/polaris-react/pull/1774))
 - Updated `ResourceList` examples to use `Filters` ([#1774](https://github.com/Shopify/polaris-react/pull/1774))
 - Added an example to `Filters` showing the use of `children` ([#1774](https://github.com/Shopify/polaris-react/pull/1774))
+- Added guidance for making animated gifs in PRs and issues more accessibility-friendly [#1998](https://github.com/Shopify/polaris-react/pull/1998)
 
 ### Development workflow