Update docs/glossary.md

Co-authored-by: Steve Piercy <[email protected]>

Author: lord2anil

docs/glossary.md

@@ -648,6 +648,7 @@ UID
    UID is an acronym meaning "unique identifier".
    A UID is an identifier that is guaranteed to be unique among all identifiers used for those objects and for a specific purpose.
 
+integer identifier
 intid
     In Plone, an integer identifier, or intid, is used to uniquely identify content objects within a Plone site.
     Each content item in a Plone site is given a unique intid, which the system uses internally to monitor and manage content.