Document available shipping integrations

[bojanz]

At some point we need a table of shipping integrations, like the one we have for payment gateways.

Current list:

    "Commerce Australia Post": "https://www.drupal.org/project/commerce_auspost",
    "Commerce Canada Post": "https://www.drupal.org/project/commerce_canadapost",
    "Commerce NZPost": "https://www.drupal.org/project/commerce_nzpost",
    "commerce colissimo shipping": "https://www.drupal.org/project/commerce_colissimo_shipping",
    "Commerce ShipEngine": "https://www.drupal.org/project/commerce_shipengine",
    "Commerce UPS": "https://www.drupal.org/project/commerce_ups",
    "Commerce FedEx": "https://www.drupal.org/project/commerce_fedex",
    "Commerce Shipping Econt": "https://www.drupal.org/project/commerce_econt",

USPS is also on the verge of a -dev release. Someone also told me of a ShipStation integration, need to follow up on that.

[bojanz]

https://www.drupal.org/project/commerce_shipping_paczkomaty
https://www.drupal.org/project/commerce_dellin