Add docs from gofiber/fiber@11c0e99

Author: github-actions[bot]

docs/core/whats_new.md

@@ -18,7 +18,7 @@ it update your project automatically:
 
 ```bash
 go install github.com/gofiber/cli/fiber@latest
-fiber migrate --to v3.0.0-rc.2
+fiber migrate --to v3.0.0-rc.3
 ```
 
 See the [migration guide](#-migration-guide) for more details and options.
@@ -1595,7 +1595,7 @@ To streamline upgrades between Fiber versions, the Fiber CLI ships with a
 
 ```bash
 go install github.com/gofiber/cli/fiber@latest
-fiber migrate --to v3.0.0-rc.2
+fiber migrate --to v3.0.0-rc.3
 ```
 
 ### Options