Adding documentation example to deprecationRule

[felipeissa]

This adds documentation example to the deprecation rule.

PR checklist

• [x ] Addresses an existing issue: rule deprecation have no example no documentation #3847
• [x ] Documentation update

Overview of change:

This adds example to the rule documentation.

CHANGELOG.md entry:

[documentation]

[palantirtech]

Thanks for your interest in palantir/tslint, @felipeissa! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[aervin]

@felipeissa It's possible to add code examples to the rule docs now. Would you consider adding code examples for this rule? Many people may be unaware of what a JSDoc is, and code examples may spark an interest. For an example of the new code example metadata setup, see the curly rule.

[felipeissa]

Sure, I can take a look on it. I'll also try to check why this test is failing 😁

[suchanlee]

I just fixed the build here: #3853