CSSFX is a collection of CSS effects with previews and very simple implementation instructions. Just click on the effect demo that you like, and a popup with HTML and CSS code snippets will appear, ready to be used on your site.
There’s also a GitHub repository, if you prefer it this way.
“Front-end Developer Handbook 2019” (and its GitHub repository) is a good place to start for everyone looking to become a front-end developer.
“The HTML we never had” is an interesting look at some features of HTML, that weren’t implemented, but could have been easily done, and if they were, how different the modern web development would be.
I agree that the “src” attribute makes a lot of sense for tags other than just images and videos.
percollate is a command-line tool to convert web pages into PDF files. It supports single-page and multi-page files, can fetch the HTML documents from the web, understands accelerated mobile pages (see AMP), and even allows some control of the output with CSS snippets.
For anyone who needs an image gallery or any scrolling list for that matter, Glider.js looks like a good option. It’s super simple to use, light, responsive, and dependency free. Have a look at some demos here.