Doc(Core): Add docstring for monomials in MOPolynomial

mapytex/calculus/core/MO/polynomial.py

@@ -79,6 +79,15 @@ class MOpolynomial(MO):
 
     @property
     def monomials(self):
+        """ Return dictionnary with degree in keys and monomial in value
+
+        :example:
+        >>> p = MOpolynomial('x', [1, 2, 3])
+        >>> p.monomials
+        {<MOnumber 0>: <MOnumber 1>, <MOnumber 1>: <MOMonomial 2x>, <MOnumber 2>: <MOMonomial 3x^2>}
+        >>> p.monomials.values()
+        dict_values([<MOnumber 1>, <MOMonomial 2x>, <MOMonomial 3x^2>])
+        """
         return self._monomials