DOC: add to to_offset the missing parameter is_period and examples (pandas-dev#56789)

add missing parameter is_period and examples to to_offsets

Author: natmokval

pandas/_libs/tslibs/offsets.pyx

@@ -4734,6 +4734,10 @@ cpdef to_offset(freq, bint is_period=False):
     Parameters
     ----------
     freq : str, datetime.timedelta, BaseOffset or None
+        The frequency represented.
+    is_period : bool, default False
+        Convert string denoting period frequency to corresponding offsets
+        frequency if is_period=True.
 
     Returns
     -------
@@ -4768,6 +4772,17 @@ cpdef to_offset(freq, bint is_period=False):
 
     >>> to_offset(pd.offsets.Hour())
     <Hour>
+
+    Passing the parameter ``is_period`` equal to True, you can use a string
+    denoting period frequency:
+
+    >>> freq = to_offset(freq="ME", is_period=False)
+    >>> freq.rule_code
+    'ME'
+
+    >>> freq = to_offset(freq="M", is_period=True)
+    >>> freq.rule_code
+    'ME'
     """
     if freq is None:
         return None