docs(migrations): add migration-guide-v0.49-to-v0.50.md

(cherry picked from commit 7e96812f5c547a9721342e503d5ee53bf0e7888d)

Author: nanang-ab

docs/migration-guides/migration-guide-v0.49-to-v0.50.md

@@ -0,0 +1,10 @@
+<a name="v0.49.0"></a>
+## [v0.49.0] - 2023-11-07
+
+### BREAKING CHANGE
+
+Following changes in OpenAPI spec:
+
+1. AMS, some operations are moved to different class
+   - import import net.accelbyte.sdk.api.ams.models.{ApiRegionsResponse -> ApiAMSRegionsResponse};
+