The tag attributes. For example, section related tags can have a label:
{start_of_verse: label="Verse 1"}
Check whether this tag's label (if any) should be rendered, as applicable to tags like
start_of_verse and start_of_chorus.
See https://chordpro.org/chordpro/directives-env_chorus/, https://chordpro.org/chordpro/directives-env_verse/,
https://chordpro.org/chordpro/directives-env_bridge/, https://chordpro.org/chordpro/directives-env_tab/
Checks whether the tag value is a non-empty string.
Checks whether the tag is a comment tag ({comment} or {c}).
Checks whether the tag is an image tag ({image}).
Checks whether the tag is a standard meta tag, a custom meta directive ({x_some_name})
or a non-standard meta tag ({meta: name value})
Checks whether the tag is usually rendered inline. It currently only applies to comment tags.
Checks whether this tag is a standard meta tag or a custom meta directive ({x_some_name})
Returns a string representation of an object.
Represents a tag/directive. See https://www.chordpro.org/chordpro/chordpro-directives/