feat(core): Model tag for Access/Role

ref: #712 #683

docs/projects/centurion_erp/user/core/markdown.md

@@ -96,6 +96,7 @@ A Model link is a reference to an item within the database. Supported model link
 | projectstate| `$project_state-<id>` |
 | projecttask| `$-<id>` |
 | projecttype| `$-<id>` |
+| role| `$role-<id>` |
 | service| `$service-<id>` |
 | software| `$software-<id>` |
 | softwarecategory| `$-<id>` |