This adds a hidden 'helm doc' command that generates documentation out
of the Helm help text.
Currently it can create:
- man pages for HELM(1)
- Markdown documentation
- bash autocompletions
Those are the three built-ins for Cobra.
The command is hidden so that it doesn't show up to the regular user,
since this is really a specialized task. It has the advantage of making
it trivially easy to install man pages and bash completion at installation time.
There were several places where an invalid name could be interpreted
into a wild-card by Kubernetes. That allows Bad Things.
This fix requires names to match the Kubernetes pattern for naming.
Closes#1594