Labels
Labels classify issues. Manage them at /:owner/:repo/labels.
Creating a label
A label has a name, a colour, and an optional description. Names are unique within a repository.
Applying labels
Apply them from an issue, or when creating one. An issue may carry any number.
Deleting a label
Deleting removes it from every issue that carries it. The issues themselves are untouched.
Names with spaces
A label named good first issue is valid. In a URL its spaces are encoded, so
prefer the API's label endpoints over hand-written URLs when scripting.