Hints for vacuumtube in testing

Hints

• asv-cid-maybe-not-rdns
  :4 - rocks.shy.VacuumTube
  The component ID might not follow the reverse domain-name schema (the TLD used by it is not known to the validator).
• asv-unknown-tag
  :7 - developer
  Found invalid tag. Non-standard tags should be prefixed with `x-`. AppStream also provides the <custom/> tag to add arbitrary custom data to metainfo files. This tag is read by AppStream libraries and may be useful instead of defining new custom toplevel or `x-`-prefixed tags if you just want to add custom data to a metainfo file.
• asv-description-first-word-not-capitalized
  :32 -
  The description line does not start with a capitalized word, project name or number.