tag: Do not allow tagging with a SemVer range as the tag name

Fix #6082
npmconf@2.0.8

disallow semver ranges in tag configuration
Changes to reflect scoped package support.
fragment sentence fix
Adding explicit GitHub examples
"As of..." instead of "currently"
All instances of config(7) to npm-config(7), scope(7) to npm-scope(7)
Adding explicit @ and / requirement for all usages of <scope>