feat: add bom.definitions

for #697

Signed-off-by: Hakan Dilek <[email protected]>

Author: hakandilek

cyclonedx/model/bom.py

@@ -561,7 +561,6 @@ def vulnerabilities(self, vulnerabilities: Iterable[Vulnerability]) -> None:
     def definitions(self) -> Optional[Definitions]:
         """
         The repository for definitions
-
         Returns:
             `Definitions`
         """