DOC: improve Timestamps docstrings (#50873)

* DOC: improve Index docstrings

* fix example

* update Series.hanans docstring

* DOC: improve docstrings

Author: abonte

pandas/_libs/tslibs/timestamps.pyx

@@ -687,6 +687,14 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return True if date is first day of the year.
 
+        Returns
+        -------
+        bool
+
+        See Also
+        --------
+        Timestamp.is_year_end : Similar property indicating the end of the year.
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -704,6 +712,14 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return True if date is last day of the year.
 
+        Returns
+        -------
+        bool
+
+        See Also
+        --------
+        Timestamp.is_year_start : Similar property indicating the start of the year.
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -785,6 +801,10 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return True if year is a leap year.
 
+        Returns
+        -------
+        bool
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -798,6 +818,10 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return day of the week.
 
+        Returns
+        -------
+        int
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -811,6 +835,10 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return the day of the year.
 
+        Returns
+        -------
+        int
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -824,6 +852,10 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return the quarter of the year.
 
+        Returns
+        -------
+        int
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -837,6 +869,10 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return the week number of the year.
 
+        Returns
+        -------
+        int
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)
@@ -850,6 +886,10 @@ cdef class _Timestamp(ABCTimestamp):
         """
         Return the number of days in the month.
 
+        Returns
+        -------
+        int
+
         Examples
         --------
         >>> ts = pd.Timestamp(2020, 3, 14)