Docs: Add isEquivalentTo example(s)

[parker-research]

Related to #380, it would be helpful to add an example of this important method. Creating this issue as a reminder to add it once Python docs are released.

Explanation:

There is an isEquivalentTo function on SyntaxNodes that compare logical equivalence (i.e. without any trivia like whitespace or comments), which is maybe what you want. Otherwise if you want a string comparison you can use the SyntaxPrinter class which has various options for controlling whether comments, trivia, preprocessed nodes, etc are included.