Add news post about new merch

content/news/merch-2024-06.md

static/img/merch/black-hoodie.png

static/img/merch/black-tshirt.png

static/img/merch/blue-hoodie.png

static/img/merch/brown-hoodie.png

static/img/merch/cardinal-tshirt.png

static/img/merch/grey-tshirt.png

static/img/merch/navy-hoodie.png

static/img/merch/navy-tshirt.png

static/img/merch/pink-tshirt.png

static/img/merch/red-hoodie.png

static/img/merch/vertical-mug.jpeg

static/img/merch/white-tshirt.png