rename rpm-md to rpm for type about zypper

[Conan-Kudo]

Type 'rpm' was reserved for apt-rpm metadata (a concatenation of rpm headers into a single file), which, admittedly, zypper doesn't support. The original name for 'rpm-md' was 'repomd' (after the repomd.xml file), and before that, it was known as the yum metadata format. apt-rpm still calls it 'repomd', while smart calls it 'rpm-md' like Zypper does.

Unfortunately, all the information about 'rpm-md' disappeared with the loss of the Duke University pages on the format at https://sites.duke.edu/linuxprojects/metadata/.

[mlandres]

Thanks for the summary. By now I see no need to rename it.

[Conan-Kudo]

@mlandres To be fair, nothing actually supports apt-rpm metadata except apt-rpm, and the type 'rpm' would probably be well-understood to equal 'rpm-md'. It could be added as an alias, like 'yum' and 'repomd' are for 'rpm-md'. If Zypper were to ever add support for apt-rpm metadata, it'd probably be called 'apt-rpm' anyway.

[mlandres]

I could allow this as an alias, but zypper output (especially XML) will continue to use rpm-md.

[Conan-Kudo]

@mlandres I don't think that's a problem.