help: mention subcommands in dabba help message.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
doc: refactor interface command POD header.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
doc: rename POD header paragraphs name.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
doc: © are not rendered in generated manpages.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>