Update article.md | changes under Comma subheading

[errwnd]

Shouldn't "a" be assigned the value of the later operation(3+4) rather than (1+2).

[CLAassistant]

All committers have signed the CLA.

[joaquinelio]

No
Read it,
precedence is the point of the smart header

let a = (1 + 2, 3 + 4) // a = (7)

let a = 1 + 2, 3 + 4 // (a = 3), 7

[errwnd]

let a = 1 + 2, 3 + 4 // (a = 3), 7
Shall we have a code representation like:
let a; a =1+2, 3+4; alert(a); // returns 3