Add leading zero to weeks 1 to 9 for nicer listing

Just a minor tweak to make the listing of the week folders nicer and test merge request functionality.

merged

mentioned in commit b8aa4248

Please test the edits running gitbook locally and previewing the results. I had to update the SUMMARY.md since you changed all links but forgot to update them in the index.

Thanks for the note. This was more of a test. Wanted to see if merge requests work the same they do on GitHub. I will test things more thoroughly next time.

I wonder if there is a way to write an automated test to check the links. Will look into that.