0.3.8 - Metadata tagging

Now you can "tag" your metadata fields with custom information, telling more about what type of data is stored in the field.
For now only is_annotation() flag is there, but more will be added soon with possibility of defining your own custom tags.

What's Changed

• Add enrichment tag annotation by @idonov8 in #348

Full Changelog: 0.3.7...0.3.8