Remove heteronormativity from coding style doc

[ddbeck]

I'm proposing replacing the gender example with a non-gendered example in the Coding style doc. The example as written makes an exclusionary implication about gender identification which might be off-putting to potential contributors who do not identify as male or female. Moreover, choices in collecting gender data is often considerably more complicated than demonstrated. A trivial coding style example is probably more clear in this case, in that it demonstrates the style, rather than substance, of expected code.

[adrianholovaty]

Thanks, @ddbeck -- good call.