Improve example that illustrates what "as" expressions are for

[felipecrv]

The previous example has an explicit Array type annotation and the example containing the "as" expression does not need that since it wants to demonstrate how the coercion can be achieved by expressing the type of the elements in the Array after with "as".

[SeanTAllen]

@jemc I'm neutral.

[jemc]

That's good enough for me. :grin:

Thanks for your contribution!