Add example usage function for pcall()

[sammygrey]

Changes

The documentation can be somewhat confusing when trying to learn how to correctly implement pcalls as pointed out by @junveld in this forum post. I have added a small piece of example code for how to use pcalls to do function calls that even when returning an error, will allow the rest of the script to continue as normal.

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[IgnisRBX]

@sammygrey
Thanks for the contribution! I just changed the pcall() param name from response to errorMessage to match what's generally used throughout our docs.