Feature request - Video Timestamps for Tutorials

Description

It would be nice if it was possible to include timestamps for WordPress.tv videos on Learn WordPress Tutorials.

WordPress.tv videos support a query variable at which allows the user to share the video at a specific timestamp

eg:

https://videopress.com/v/uJVeAMVC?at=120

will start the video at the 2-minute mark.

Adding the additional autoPlay query var will also automatically play the video

https://videopress.com/v/uJVeAMVC?at=120&autoPlay=1

It would be great if we could somehow accept the same (or a similar) query variable on the URL for Learn WordPress tutorials and pass it to the iframe that WordPress embeds into the page content for the tutorial.

eg:

https://learn.wordpress.org/tutorial/customizing-a-header-with-patterns/?at=120&autoPlay=1

This would allow content creators to create linkable timestamps as part of the tutorial's written portion, allowing visitors to jump to specific sections of the tutorial quickly.

Additional Information

Learn WordPress uses the content-workshop-single.php template part to render the video tutorial.

wp-content/themes/pub/wporg-learn-2020/template-parts/content-workshop-single.php

It used the WordPress Embed class and the default WordPress embed functionality to create the embeddable iframe that is rendered on the front end

Line 32

It implements the $wp_embed->autoembed( $post->video_url );

Where the $post->video_url is the URL the user adds in the WordPress.tv URL Sidebar setting on the post editor. In testing, it is possible to add the source video URL with the two query parameters to that setting area, and the video will jump to the specific time and autoplay.

Requirements

1. Update the Tutorial functionality on Learn WordPress to accept two additional URL/query parameters for the at and autoPlay values
2. If either of these parameters is set, append them to the $post->video_url URL just before it's passed to the $wp_embed object's autoembed method.

Start in wp-content/themes/pub/wporg-learn-2020/template-parts/content-workshop-single.php, especially the $wp_embed->autoembed( $post->video_url ) call. Trace how the tutorial page receives URL query parameters, then verify that at and autoPlay are passed to the embedded video when present. Done means timestamped tutorial URLs jump to the requested time and optionally autoplay without those parameters breaking normal embeds.