Paymentlink doc correction

[ankitdas13]

Create a standard payment link (sdk audit) : update

Create a UPI payment link (sdk audit) : UPI Payment Links is not supported in Test Mode. Please experience the product in Live Mode.

Update a Payment link (sdk audit) : update

Transfer payments received using payment links (sdk audit) : {"accept_partial":false,"amount":3400,"amount_paid":0,"cancelled_at":0,"created_at":1656660483,"currency":"INR","customer":{"contact":"+919999999999","email":"gaurav.kumar@example.com","name":"Gaurav Kumar"},"description":"Payment for policy no #23456","expire_by":0,"expired_at":0,"first_min_partial_amount":0,"id":"plink_Jo1G3P24on5U4L","notes":null,"notify":{"email":true,"sms":true},"payments":null,"reference_id":"#428","reminder_enable":false,"reminders":[],"short_url":"https://rzp.io/i/mvUmTVeo","status":"created","updated_at":1656660483,"upi_link":false,"user_id":""} Put receipt unique

offers on payment links (sdk audit) : Put receipt unique

Managing remainders for payment (sdk audit) : Put receipt unique

Rename labels in checkout section (sdk audit) : Put receipt unique

Change Business name and desciption (sdk audit) : Put receipt unique

Prefill checkout fields (sdk audit) : Put receipt unique

Customize Payment methods (sdk audit) : Put receipt unique

Set checkout fields as readonly (sdk audit) : Put receipt unique

Implement Thematic Changes in payments links checkout section (sdk audit) : Put receipt unique

Rename Labels in payment details section (sdk audit) : change expiry_by atleast 15 min + and receipt paramter unique