docs(core): add nx overview video to Nx docs

docs/shared/getting-started/why-nx.md

@@ -1,5 +1,10 @@
 # Why Nx?
 
+{% youtube
+src="https://www.youtube.com/embed/-_4WMl-Fn0w"
+title="What is Nx?"
+width="100%" /%}
+
 We created Nx because developers struggle to configure, maintain and especially integrate various tools and frameworks. Setting up a system that works well for a handful of developers and at the same time, easily scales up to an entire organization is hard. This includes setting up low-level build tooling, configuring fast CI, and keeping your codebase healthy, up-to-date, and maintainable.
 
 We wanted to provide a solution that is easy to adopt and scale.