Description

When a merchant gets a dispute with reason 'duplicate', a 'Duplicate charge info' section will appear on the dispute evidence form page.

In that section, merchant needs to specify a duplicate charge id. Read more on Stripe's docs.

#8100 shows charge id on payment details page but that might not be trivial to merchants.

In that PR I attempted to add a docs to explain:

• What 'duplicate charge info' section on the evidence form is about.
• How to find the charge id on the payments details page (and since which version it is available).
• Any other useful information like tips on how to find duplicate charges, eg find transactions from the same customers or within the nearby time range, etc.
• That the charge id input to the field needs to start with ch_ (otherwise, Stripe will throw an error).

But since that would be out-of-scope, I create this issue instead.

Acceptance criteria

• We have a guidance for merchant how to fill out the 'Duplicate charge info' section on the dispute evidence form page.