Calibration tutorial link in JOSS paper is broken

[peanutfun]

Describe the issue
The link to the tutorial in the JOSS paper is broken. We were only able to use the link to the PR doc preview during the review process. Readthedocs now has deleted this preview and the link is dead:

climada_python/doc/joss/calibration-module/paper.md

Line 144 in e4a3cfd

[^2]: See \url{https://climada-python--692.org.readthedocs.build/en/692/tutorial/climada_util_calibrate.html}.

See https://joss.theoj.org/papers/10.21105/joss.06755

How to fix this
We can update the link in the paper source within the CLIMADA repo and ask JOSS to re-render the publication on their end. This was possible for another publication with a similar issue, see openjournals/joss-reviews#2165 (comment)

I would wait until the ongoing effort to restructure the documentation (#977) is resolved, to be sure that the new link will remain "stable". Another option is to simply remove the link and reference the entire documentation instead.

@chahank @timschmi95