Add no-ok-equality examples using allowGlobals option

[platinumazure]

The no-negated-ok docs don't have any examples to show how the checkBooleanAssertions and allowGlobals options work.

[bmish]

This ticket is obsolete and can be closed due to #197.

[platinumazure]

@bmish The allowGlobals option is still present even after #197, and we could use examples there. So I've edited the title but I will leave this open. Thanks!