3.7 Release Notes - fix typo

[greg-murray-volusion]

For this sample comparing to type predicates:

if (isString(str)) {
    return str.toUppercase();
}

I believe you meant to put the correct method str.toUpperCase();

Fixes # 1276

[msftclas]

All CLA requirements met.

[orta]

Hi - this is going into a branch which isn't master, and so it won't get applied to the main repo!

If you switch the PR's base branch to master then it'd probably be good to merge 👍

[orta]

perfect, thanks