bpo-31327: Update time documentation to reflect possible errors (GH-31460)

As per the comments, this mirrors the [datetime documentation](https://docs.python.org/3/library/datetime.html#datetime.datetime.fromtimestamp). 

```
>>> import time
>>> time.localtime(999999999999999999999)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OverflowError: timestamp out of range for platform time_t
>>> time.localtime(-3600)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OSError: [Errno 22] Invalid argument 
```

Doc/library/time.rst

@@ -257,6 +257,12 @@ Functions
    :const:`None`, the current time as returned by :func:`.time` is used.  The dst
    flag is set to ``1`` when DST applies to the given time.
 
+   :func:`localtime` may raise :exc:`OverflowError`, if the timestamp is
+   outside the range of values supported by the platform C :c:func:`localtime`
+   or :c:func:`gmtime` functions, and :exc:`OSError` on :c:func:`localtime` or
+   :c:func:`gmtime` failure. It's common for this to be restricted to years
+   between 1970 and 2038.
+
 
 .. function:: mktime(t)