Render url with .md to correct link

[cmd-ntrf]

Links referring to other 2i2c blog posts are currently returning a 404 because they are improperly rendered.

Example of two links in Improvements to our team's planning and delivery

<a href="../../2023/organizational-report/index.md">our 2023 report of organizational strengths and weaknesses</a>

<a href="../../2023/organizational-report/index.md">released a report describing our organizational strengths and weaknesses</a>

I am not a Hugo expert, so I had to Google a solution, which I have included in this PR.

Also note that the GitHub link checker workflow appears to miss these broken links. I have yet found why as lychee was acting weirdly on my laptop.

[choldgraf]

This is super cool, thanks for taking a look at it. First off, I've just merged a PR to fix these links here:

• Fix several incorrect links to md files #247

For future-proofing this, I think this PR could be very helpful, but it'll need an iteration because it currently breaks our external links :-)

I suggest that if you think you can resolve that issue with less than 30 minutes of thinking, let's go for it! But if it'll be too complex because writing Hugo is very confusing, we don't have to worry about it (one day I wanna switch these blog docs to MyST :-) )

[cmd-ntrf]

Took me less time to fix this PR than the time to read that excellent blog post, so net positive.

[choldgraf]

Thanks so much, this is really helpful! I added a quick TYVM to the code :-D