Migrate `assertj-neo4j` documentation

[PaulienVa]

When checking out the website I noticed a neo4j module was there 🥳 , but when clicking on the section, is appaered to be empty:

I could not find any github repository for this module as well, maybe a premature release of the docs?

Will there be a module for neo4j assertion? If so, when is it coming up?

[scordio]

assertj-neo4j exists under Joel's account and with its corresponding documentation.

Unfortunately, the project leads haven't had the time to maintain the module in the past years. Nevertheless, we should probably move the project and migrate the documentation.

WDYT @joel-costigliola?