Add legal code references for NYC School Tax Credit parameters

[MaxGhenis]

Currently tax form only

[MaxGhenis]

Here's a case where the legal code could help clarify. The STC fixed amount limits based on income, which it defines as AGI. But the rate reduction amount limits based on "income":

If you are a New York City resident or part-year resident and you marked the Yes box at item C on the front of Form IT-201 indicating that you can be claimed as a dependent on another taxpayer’s federal return, or your income (see below) is more than $500,000, you do not qualify to claim this credit

The (see below) does not refer to anything; there's no additional definition. While the tables suggest it's limited on taxable income, the legal code probably clarifies: