Add Step 5: Runtime-Configurable URLs

[bredikhin]

• add the code for Step 5
• add the slides for the exercises

(re: https://github.com/nearform/hub-draft-issues/issues/283)

from https://nearform.slack.com/archives/C05FV2WQN6T/p1689690761966319?thread_ts=1689689745.016189&cid=C05FV2WQN6T:

Coston
@Matteo Pietro Dazzi what approach for demonstrating “run-time configurable URLs” do you recommend?

Matteo Pietro Dazzi
the old approach is through the external-remotes-plugin, while the new one is through the @module-federation/utilities package

...
Matteo Pietro Dazzi
@Coston Maybe something like:
1 host
2 remotes: named remote-a and remote-b
Initially you load remote-a, and once you press a button and reload the page thanks to the "run-time configurable URLs" you load remote-b without changing any of the MFE configuration.
Just to simulate something like a-b testing or the strangler pattern