Whenever I onboard to a new codebase, or try to learn more about an open-source project, I typically create personal notes that outline the structure and high-level “markers” that I want to remember and easily reference later.

Unfortunately those notes are disconnected from the codebase itself, and therefore, not as immersive/rich as I wanted them to be. So I created a tool that allows me to annotate codebases with my own walkthroughs/breadcrumbs/ToCs and then play them back at any time, directly within my editor. This workflow has provided a pretty nice productivity boost for me thus far, and has the benefit of enabling me to share these walkthroughs with others as well: https://github.com/vsls-contrib/codetour.