Add override exception for interface functions.

docs/contracts/inheritance.rst

@@ -303,6 +303,13 @@ contracts can no longer change the behaviour of that function.
   outside of interfaces. In interfaces, all functions are
   automatically considered ``virtual``.
 
+.. note::
+
+  Starting from Solidity 0.8.8, the ``override`` keyword is not
+  required when overriding an interface function, except for the
+  case where the function is defined in multiple bases.
+
+
 Public state variables can override external functions if the
 parameter and return types of the function matches the getter function
 of the variable:

docs/contracts/interfaces.rst

@@ -33,10 +33,10 @@ Interfaces are denoted by their own keyword:
 
 Contracts can inherit interfaces as they would inherit other contracts.
 
-All functions declared in interfaces are implicitly ``virtual``, which means that
-they can be overridden. This does not automatically mean that an overriding function
-can be overridden again - this is only possible if the overriding
-function is marked ``virtual``.
+All functions declared in interfaces are implicitly ``virtual`` and any
+functions that override them do not need the ``override`` keyword.
+This does not automatically mean that an overriding function can be overridden again -
+this is only possible if the overriding function is marked ``virtual``.
 
 Interfaces can inherit from other interfaces. This has the same rules as normal
 inheritance.