Add detail to JSON dump-package command

Signed-off-by: Keshav Priyadarshi <git@keshav.space>

Co-authored-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: keshav-space

src/packagedcode/swift.py

@@ -20,7 +20,8 @@
 https://docs.swift.org/package-manager/PackageDescription/PackageDescription.html
 
 Run the commands below before running the scan:
-``swift package dump-package > Package.swift.json``
+
+-  To create a parsable JSON version of the Package.swift manifest, run this: ``swift package dump-package > Package.swift.json``
 ``swift package resolve``
 """