add post on adding video callouts to markdown readmes on GitHub

chan.dev/src/content/posts/add-video-to-github-readme.md

@@ -0,0 +1,109 @@
+---
+title: Add video to GitHub README
+publishDate: 2024-07-22
+references:
+  - https://stackoverflow.com/questions/11804820/how-can-i-embed-a-youtube-video-on-github-wiki-pages
+  - https://www.get-youtube-thumbnail.co/
+  - https://stackoverflow.com/questions/34763547/youtube-maxresdefault-thumbnails
+---
+
+YouTube videos can't be embedded in GitHub READMEs.
+
+## TL;DR
+
+## Contents
+
+## Basic markdown implementation (no styles)
+
+Start by uploading a thumbnail image.
+
+_Note:If you make this change via the GitHub UI, they'll host uploaded images without requiring they be added to the repository)._
+
+You should have an image like this:
+
+```markdown
+![Uploaded image](https://github.com/user-attachments/assets/{some-slug})
+```
+
+## Make image contents a link
+
+Wrap the image markdown in a link to YouTube video.
+
+```markdown
+[![Uploaded image](https://github.com/user-attachments/assets/{some-slug})](https://youtu.be/u3KukBymauk?feature=shared)
+```
+
+## Provide a meaningful alt text
+
+I prefer to use the video title with the prefix: `YouTube tutorial: `.
+
+```markdown
+[![YouTube tutorial: Do the thing the right way, from the beginning](https://github.com/user-attachments/assets/97ad27be-d9e7-446a-b7ed-3a220ed8f3aa)](https://youtu.be/u3KukBymauk?feature=shared)
+```
+
+## Rely on default styling
+
+If you upload a large enough image, GitHub's default styling will make the image responsive to the container.
+
+```css
+.markdown-body img {
+	max-width: 100%;
+	box-sizing: content-box;
+	background-color: var(
+		--bgColor-default,
+		var(--color-canvas-default)
+	);
+}
+```
+
+## Take styling into your own hands
+
+To take styling into your own hands, you'll need to do all this with HTML instead of markdown.
+
+You can use the markup that GitHub uses.
+
+```html
+<a href="YOUR_VIDEO_URL"
+	><img
+		src="YOUR_THAUMBNAIL_IMAGE_URL"
+		alt="YOUR_ALT_TEXT"
+		style="max-width: 100%;"
+/></a>
+```
+
+I've added a `width` rule to make sure the image is always scaled to full-width.
+
+```html ins=/width: 100%; /
+<a href="YOUR_VIDEO_URL"
+	><img
+		src="YOUR_THAUMBNAIL_IMAGE_URL"
+		alt="YOUR_ALT_TEXT"
+		style="width: 100%; max-width: 100%;"
+/></a>
+```
+
+\*Note: Most attributes get sanitized away. So there's not a whole lot else you can do.
+
+## If you don't have a thumbnail, get the one from YouTube
+
+[This site will get the YouTube hosted thumbnails for your video](https://www.get-youtube-thumbnail.com/).
+
+**Note: This URL differs slightly from those used on YouTube. The subdomain is `i3` instead of `i`.**
+
+## More than you care to know on YouTube thumbnail url schemas
+
+YouTube offers a number of thumbnail quality alternatives.
+
+[Great stack overflow on the topic of YouTube thumbnail URLs](https://stackoverflow.com/questions/34763547/youtube-maxresdefault-thumbnails).
+
+```txt
+https://i.ytimg.com/vi_webp/<VIDEO_ID>/maxresdefault.webp
+https://i.ytimg.com/vi/<VIDEO_ID>/maxresdefault.jpg
+https://i.ytimg.com/vi/<VIDEO_ID>/hqdefault.jpg
+```
+
+**Note: `maxresdefault` variants aren't guaranteed to be available. But they should be if you're uploading your own thumbnail — which you should be.**
+
+## Improve visual hints
+
+For this use case, I'm exporting a variant of my thumbnail with a "play button" overlay.