docs(event-handler): general improvements

[dreamorosi]

Summary

Changes

Please provide a summary of what's being changed

This PR improves the Event Handler docs by adding descriptions and examples for all features currently supported, as well as providing some light descriptions - and in some cases workarounds - for features we don't support yet. For the latter, I also link to the relevant issue so that readers can follow along with the progress.

For the most part, except a couple minor cases, the code examples reflect the current state of the Event Handler. There are however at least 2 code snippets that currently have linting issues which will be solved by issues we're already working on early next/this week.

In cases where features we added like compression and cors made the examples obsolete, I took the liberty to update the code examples with new content.

I suggest reviewers to pull the branch and run the docs locally to review effectively.

Please add the issue number below, if no issue is present the PR might get blocked and not be reviewed

Issue number: closes #4475

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[svozza]

Suggested change

	You can use the `errorHandler()` method as higher-order function or class method decorator to define a custom error handler for errors thrown in your route handlers or middleware.
	You can use the `errorHandler()` method as a higher-order function or class method decorator to define a custom error handler for errors thrown in your route handlers or middleware.

[svozza]

Suggested change

	As applications grow and the number of routes a Lambda function handles increases, it becomes natural to either break into smaller Lambda functions or split routes into separate files to ease maintenance.
	As applications grow and the number of routes a Lambda function handles increases, it becomes natural to either break it into smaller Lambda functions or split routes into separate files to ease maintenance.

[svozza]

Two very minor comments but other than that LGTM!