Mermaid diagram for RIPER-5 flow

[withkynam]

Create a Mermaid flowchart showing the RIPER-5 phase progression (Research, Innovate, Plan, Execute, Update Process) with decision points.

Difficulty: Easy | Time: ~1-2h | Mentor: @withkynam

Note: The README already has some Mermaid diagrams -- this is for a standalone, more detailed version.