refactor: doctype naming

Overdue Payments -> Overdue Payment
diff --git a/erpnext/accounts/doctype/dunning/dunning.json b/erpnext/accounts/doctype/dunning/dunning.json
index a0ddf04..b609a5c 100644
--- a/erpnext/accounts/doctype/dunning/dunning.json
+++ b/erpnext/accounts/doctype/dunning/dunning.json
@@ -277,7 +277,7 @@
    "fieldname": "overdue_payments",
    "fieldtype": "Table",
    "label": "Overdue Payments",
-   "options": "Overdue Payments"
+   "options": "Overdue Payment"
   },
   {
    "fieldname": "section_break_28",
diff --git a/erpnext/accounts/doctype/overdue_payments/__init__.py b/erpnext/accounts/doctype/overdue_payment/__init__.py
similarity index 100%
rename from erpnext/accounts/doctype/overdue_payments/__init__.py
rename to erpnext/accounts/doctype/overdue_payment/__init__.py
diff --git a/erpnext/accounts/doctype/overdue_payments/overdue_payments.json b/erpnext/accounts/doctype/overdue_payment/overdue_payment.json
similarity index 98%
rename from erpnext/accounts/doctype/overdue_payments/overdue_payments.json
rename to erpnext/accounts/doctype/overdue_payment/overdue_payment.json
index 57104c1..e5253bd 100644
--- a/erpnext/accounts/doctype/overdue_payments/overdue_payments.json
+++ b/erpnext/accounts/doctype/overdue_payment/overdue_payment.json
@@ -161,7 +161,7 @@
  "modified": "2021-09-15 19:04:54.082880",
  "modified_by": "Administrator",
  "module": "Accounts",
- "name": "Overdue Payments",
+ "name": "Overdue Payment",
  "owner": "Administrator",
  "permissions": [],
  "quick_entry": 1,
diff --git a/erpnext/accounts/doctype/overdue_payments/overdue_payments.py b/erpnext/accounts/doctype/overdue_payment/overdue_payment.py
similarity index 84%
rename from erpnext/accounts/doctype/overdue_payments/overdue_payments.py
rename to erpnext/accounts/doctype/overdue_payment/overdue_payment.py
index 844f8ec..e3820d7 100644
--- a/erpnext/accounts/doctype/overdue_payments/overdue_payments.py
+++ b/erpnext/accounts/doctype/overdue_payment/overdue_payment.py
@@ -4,5 +4,5 @@
 # import frappe
 from frappe.model.document import Document
 
-class OverduePayments(Document):
+class OverduePayment(Document):
 	pass