Document configuration name error

[zhangjianweibj]

documents comment:

sidecar configs are identified by a requesting

annotation, like:

"injector.tumblr.com/request=tumblr-php"

the "name: tumblr-php" must match a configuration below;

but configuration is name: "test"

[byxorna]

@newfurniturey @zhangjianweibj has previously signed the CLA, so this is good to merge (https://github.com/tumblr/k8s-sidecar-injector/pull/22#issuecomment-533032419).

[newfurniturey]

@byxorna hold off on that for a moment; we may need to have our new CLA signed first (new parent company, new rules). Getting clarification at this time, can update here when I have more info

[alex-laties]

stale, will fix in a separate commit. thanks for bringing it to our attention!