PEP 3104: Add footnote to give example

[SA-WS]

While reading PEP 3104 to understand the nonlocal keyword, I found the explanation for why an alternative was not chosen to be vague. Further digging revealed an example for why there was a concern that .x and x could be used interchangeably. I linked this example as a footnote to save future readers time from digging to find an example. I hope this will increase comprehension of the PEP for future learners.

[the-knights-who-say-ni]

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[gvanrossum]

Thanks! This is a worthy improvement. Even though we normally don't change PEPs after the fact (other than to fix typos or stale links), I am accepting this.

I hope you will still apply for the CLA.

[SA-WS]

Thanks! This is a worthy improvement. Even though we normally don't change PEPs after the fact (other than to fix typos or stale links), I am accepting this.

I hope you will still apply for the CLA.

Thank you! Happy to contribute, CLA applied for!