VS Code allows extensions to contribute different icon themes, and vscode-icons provides a rich set of custom icons that are highly recognizable for a vast array of programming languages.

Once you've tested your final extension code, to use it you just need to package it in a local .vsix file for your own use, as opposed to publishing it to the VS Code Marketplace.

VS Code, with the right set of extensions, has turned from a mere code editor into my writing companion. It started as an experiment but quickly evolved into a core part of my daily routine.