README still points to WALTKTHROUGH

[maeriens]

I'm scouring the internet to understand how to build a VSCode extension for some embedded syntax highlighting.
On that search, I came across this repo. Not what I am searching - but wanted to point out there are a few links around the internet that point to the now defunct WALKTHROUGH file, now renamed SPEEDRUN, and so does the very same readme of the repo.
I believe GitHub's markdown allow you to do something like

Interested in how this extension was made, you can see the 5 minute [speed run walkthrough](SPEEDRUN.md)