docs: mermaid roadmap

Author: cheina97

ROADMAP.md

@@ -6,6 +6,16 @@ tl;dr
 - Liqo **1.0.0-rc4**: March 2025
 - Liqo **1.0.0 final**: Late spring 2025
 
+```mermaid
+gantt
+    title Liqo Release Schedule
+    dateFormat  YYYY-MM-DD
+    section Releases
+    v1.0.0-rc3  :active, rc3,   2024-12-10, 2024-12-20
+    v1.0.0-rc4  :        rc4,   after rc3,  2025-03-31
+    v1.0.0      :        final, after rc4,  2025-06-01
+```
+
 The next release of Liqo (`v1.0.0`) will include many breaking changes, due to the necessity to bring more modularity and flexibility to the project, a cleaner and more granular control (e.g., fully declarative APIs to control the most important features of Liqo), and other features.
 Even more important, the Liqo team believes that the project is now mature and stable enough to be safely deployed in production environments, and to consolidate most of its APIs that were defined as `alpha` in the past. This is reflected in the change in the numbering of the Liqo version, now `v1.0.0`.
 Therefore, the Liqo team has decided to publish incremental release candidates for this version, allowing early adopters to discover and test the new features in advance, hence potentially reducing the disruption (and painful migration strategies) to the current adopters.