docs: brief definition on actors

Author: Xiphereal

README.md

@@ -8,6 +8,12 @@ Use cases:
 
 ![Uses cases of a task management application](http://www.plantuml.com/plantuml/proxy?cache=no&src=https://raw.githubusercontent.com/Xiphereal/SGjsdfgklj/refs/heads/trunk/Docs/UseCases.puml)
 
+Actors definition:
+
+- Stakeholder: anyone interested in the project.
+- Product owner: the role responsible for having the final word on product related decisions.
+- User: anyone using the project manager application.
+
 > [!NOTE]
 > These are a beforehand sketch of the ideal use cases. Not all are, nor will be, implemented.