Added extra information in the readme for mock paths parameter

[NiLSPACE]

I was confused why my scenario didn't find any commands, but the custom implementations weren't loaded. This info was missing in the readme.

[NiLSPACE]

The links to AutoAPI.zip and ManualAPI.zip also don't work anymore, but I couldn't find replacement URL's.

[mathiascode]

The links to AutoAPI.zip and ManualAPI.zip also don't work anymore, but I couldn't find replacement URL's.

Maybe the artifacts had expired? The links work on my end:

• https://ci.appveyor.com/api/projects/cuberite/cuberite/artifacts/AutoAPI.zip?job=Windows-x64&pr=false&branch=master
• https://ci.appveyor.com/api/projects/cuberite/cuberite/artifacts/ManualAPI.zip?job=Windows-x64&pr=false&branch=master

[NiLSPACE]

The readme refers to

• https://builds.cuberite.org/job/Cuberite%20Windows%20x64%20Master/lastSuccessfulBuild/artifact/AutoAPI.zip
• https://builds.cuberite.org/job/Cuberite%20Windows%20x64%20Master/lastSuccessfulBuild/artifact/ManualAPI.zip

Which both don't work anymore. Shall I change that in this PR as well?

[mathiascode]

Sorry, I forgot that the README contains those links. That would be https://github.com/cuberite/CuberitePluginChecker/issues/40.

You could change them. Better to have links that work, even if they're not ideal.