Update README.md

Fix link to docs
Merge pull request #1299 from marcaube/patch-1

[InventoryBundle] Fix link to docs
Translation shipping calculator
Merge pull request #1304 from Wasper/shipping-calculator

[ShippingBundle] Translation shipping calculator options
Missing breadcrumb translation key
Coupon translations
Merge pull request #1306 from elliot/bug/missing-translations

Missing translations
[WebBundle] Added missing translation

Added missing credit card header translation (for PayumBundle > Resources > views > Payum > Action > obtainCreditCard.html.twig)
Merge pull request #1309 from boskee/missing-credit-card-translation

[WebBundle] Added missing translation
[OrderBundle] Fixed #1187. Don't generate order number if it already exists

This fixes #1187 - order number should not be re-generated if it's already assigned
Merge pull request #1311 from boskee/duplicate-order-number-fix

[OrderBundle] Fixed #1187. Don't generate order number if it exists
Merge branch 'master' of https://github.com/Sylius/Sylius