Add: Throttling. 100-migration-strategies.md (#2070)

* Add Throttling description

* Update content/roadmaps/101-backend/content/123-scalability/100-mitigation-strategies.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/101-backend/content/123-scalability/100-mitigation-strategies.md

@@ -1 +1,3 @@
-# Mitigation strategies
+# Mitigation Strategies
+
+This section is mainly relevant to the cloud design patterns that help you build scalable solutions. Have a look at the [Cloud Design Patterns](https://learn.microsoft.com/en-us/azure/architecture/patterns/) docs by Microsoft and this video covering [the throttling, retry and circuit breaker patterns](https://www.youtube.com/watch?v=0HoTGgb5oFg)