Crafting Your Own Snippets with Emacs Built-In Abbrev Mode

In the world of text editing and programming, templating is a
superpower. It saves keystrokes, reduces errors, and lets you
focus on the bigger picture. For Emacs users, battle-tested packages
like yasnippet and tempel are often the go-to solutions, offering
powerful features and extensive libraries.

But what if you're in the mood for a little crafting? What if ...