added blank line to ensure markdown does create an unordered list (ma…

…ndatory)

Chapters/5.Core_identifiers.md

@@ -151,6 +151,7 @@ As an example, `swh:1:rev:309cf2674ee7a0749978cf8265ab91a60aea0f7d` is the SWHID
 Some revisions get selected by developers as denoting important project milestones known as “releases”. Each release points to the last commit in project history corresponding to that release and carries metadata: release name and version, release message, cryptographic signatures, and so forth. If they're not attached to development history (for instance, if they've been imported from bare archive files), releases can also point directly to a root directory instead of a full revision with metadata.
 
 The metadata fields supported by SWHID are as follows:
+
 - name (arbitrary byte sequence, mandatory): a name identifying the release
 - author (arbitrary byte sequence): generally contains the name and email address of the author of the release.
 - author timestamp (decimal timestamp from the Unix epoch): the date at which the release was authored.