Document the _proto directory

[timthelion]

I'm only guessing on the use of the rudder service definition. I tried googling to no avail and neither https://github.com/timthelion/helm/blob/master/_proto/hapi/rudder/rudder.proto nor https://github.com/helm/helm/blob/master/cmd/rudder/rudder.go explain it.

[timthelion]

I wonder why the contents of verison.proto are not in tiller.proto. It is confusing to have it in the top level dir when a chart versions are encoded differently (as strings https://github.com/helm/helm/blob/master/_proto/hapi/chart/metadata.proto#L51) .

I also don't understand why the rudder directory is not in the services directory when it is in the services package.

[timthelion]

Can someone with the correct credentials hit the rebuild button? I don't think that should be failing.

[bacongobbler]

Just as a note, we do make a note of this in the developer's guide, though I can see why a README may be useful.

[timthelion]

The README would not be nearly as useful if the directory name did not start with an underscore and was instead something descriptive like protobuf ;). At first glance, I disregarded the directory as being some auto-generated set of files which had been committed either by mistake or due to the difficulty of installing the utility that so generated them.

[timthelion]

There is only one other directory which has an unclear name, rootfs and that too has a README file explaining its purpose.