Syntax
[purchase_collection
taxonomy="| taxonomy - Taxonomy name"
terms="| terms - Taxonomy terms"
text="Purchase All Items| link text - Text for link to purchase all items"
style="button| plain - Button style"
color="dark-gray| white| gray| red| green| yellow| orange| dark-gray| inherit - Button color"
class="edd-submit| CSS classes - One or more custom CSS class names"]