Add links to project code

[synapticarbors]

I thought it would be useful to have the links to the code repositories for each project available in the README rather than having to look in the pdf.

[Yura52]

Hi! Thank you for the pull request, and sorry for the slow reply. There is a bit of uncertainty about how rtdl should look like, and I expect this uncertainty to be resolved in the foreseeable future. Until then, I suggest waiting with merging this pull request, does it sound good?

[synapticarbors]

It's completely fine with me to wait. I had just collected the links out the pdfs for my own convenience and thought others might find it useful. When you decide how you want to handle it, if you need changes to this PR or a new PR, just let me know.

[Yura52]

Hi @synapticarbors ! Thank you once again for the suggestion, now, the table also provides the links to code.