Add provider for Regionalimmobilien24

[gorgobacka]

Website: https://www.regionalimmobilien24.de/

This is my first own provider. Please let me know, if something can be improved.

[orangecoding]

@gorgobacka That's a perfect pr ;) As I have merged your previous pr, this one is now having a small conflict. Once resolved, I'll merge it as well. Thanks!

[gorgobacka]

@orangecoding Thanks a lot for checking. I rebased the branch onto master.

[orangecoding]

@gorgobacka Now the test is failing. Please run it locally.

  1) #regionalimmobilien24 testsuite()
       should test regionalimmobilien24 provider:
     TypeError: Cannot read properties of undefined (reading 'enabled')
      at Module.init (file:///home/runner/work/fredy/fredy/lib/provider/regionalimmobilien24.js:40:33)
      at Context.<anonymous> (file:///home/runner/work/fredy/fredy/test/provider/regionalimmobilien24.test.js:14:14)

[gorgobacka]

Oh, no. An "o" got lost during the rebase. Sorry for this stupid mistake. Next time, I will be more careful.

It's fixed now.

[orangecoding]

Thanks!