Add a user guide on payments

doc/user/payments/banktransfer.rst

@@ -0,0 +1,31 @@
+.. _`banktransfer`:
+
+Bank transfer
+=============
+
+To accept payments with bank transfer, you only need to fill one important field in pretix' settings: In "Bank
+account details" you should specify everything one needs to know to transfer money to you, e.g. your IBAN and BIC,
+the name of your bank and for international transfers, preferably also your address and the bank's address.
+
+pretix will automatically tell the user to include the order code in the payment reference so incoming transfers can
+automatically be matched to payments.
+
+Importing payment data
+----------------------
+
+The easiest way to import payment data is to download a CSV file from your online banking. Most banks provide a CSV
+export of some sort. You can go to "Import bank data" in pretix to upload a new file:
+
+.. image:: img/bank1.png
+
+If you upload a file for the first time, pretix will not know what information is contained in which column as every
+bank builds completely different CSV files. Therefore, pretix will ask you for that information. It will show you the
+data of the file you imported and ask you to define the column's meanings. You can select one column that contains
+the payment date and one that contains the paid amount. You can select multiple columns that contain information
+about the payer or the payment reference. All other columns will be ignored.
+
+Once you continue, pretix will try to match the payments to the respective orders automatically. It will tell you how
+many orders could be processed correctly and how many could not. You can then go back to the upload page to see all
+transfers from your bank statement that are not yet matched to an order. Using the input field and the buttons on the
+left of each transaction, you can manually enter an order code to match it to or just discard it from the list, e.g.
+if the transaction is not related to the event at all.