Create validator for unnecessary meta tags

@tantek and I, among other participants in the IndieWeb community, were discussing unnecessary meta tags on websites. Unnecessary meta tags may be duplicative, oriented around a particular service, or provide little to no use to users.

It would be great if the indiewebify tool had a feature to audit the meta tags on a website and make suggestions about what could be removed that may not be useful. For instance, I decided to remove Twitter image and description tags because I had the same information in other meta tags.

The tool should make suggestions rather than warnings. The goal would be to encourage people to consider the value of the meta tags they have to them and their audience.

The issue names no files or tests. Start by locating the indiewebify tool's existing meta-tag auditing path and review how it reports findings. Define which tags qualify as unnecessary and confirm that the completed audit presents suggestions rather than warnings.

Written by the indexing model from the issue text.