Page Six may be compensated and/or receive an affiliate commission if you buy through our links. Halsey’s new beauty line is “So Good.” On Monday, the indie pop star, who uses she/they pronouns, launched af94 with 12 festival-ready, under-$10 makeup must-haves. An amalgamation of their initials (AF, for Ashley Frangipane) and birth year (1994), the…