Fix option configuration examples

[jfmengels]

Fix option configuration examples : prepend rules with "ava/".

FMI: Do you guys prefer to always add code via PRs, or can/should I push this kind of simple fix directly on master? There's no contribution guidelines for maintainers or anything, so I don't know what you agreed on.

[jamestalmage]

If it's obvious or trivial, you can just push to master. Especially if it's just documentation.

Remember, you can't fix mistakes with a --force push on master (that is a big no-no), you have to push a separate "fixup" or "revert" commit. There are lots of ways something can go wrong (you forgot to run the linter one last time, you forgot to save that new dependency in package.json, you forgot some language feature isn't supported in node 0.10, etc), so I usually prefer to just do a PR, or push to a separate branch on the main repo and verify CI passes before merging.

[novemberborn]

I like seeing PRs for everything. Helps disseminate knowledge. For the obvious/trivial ones it's fine if you merge them straight away.

[novemberborn]

There's no contribution guidelines for maintainers or anything, so I don't know what you agreed on.

Would be good to add these!

[jfmengels]

I like seeing PRs for everything. Helps disseminate knowledge.

👍

For the obvious/trivial ones it's fine if you merge them straight away.

Also 👍. I'll merge this then.