DOC finally....

skimage/feature/greycomatrix.py

@@ -128,9 +128,8 @@ def greycoprops(P, prop='contrast'):
     - 'ASM': :math:`\\sum_{i,j=0}^{levels-1} P_{i,j}^2`    
     - 'energy': :math:`\\sqrt{ASM}`
     - 'correlation':
-
-.. math:: \\sum_{i,j=0}^{levels-1} P_{i,j}\\left[\\frac{(i-\\mu_i) \\ 
-          (j-\\mu_j)}{\\sqrt{(\\sigma_i^2)(\\sigma_j^2)}}\\right]
+        .. math:: \\sum_{i,j=0}^{levels-1} P_{i,j}\\left[\\frac{(i-\\mu_i) \\ 
+                  (j-\\mu_j)}{\\sqrt{(\\sigma_i^2)(\\sigma_j^2)}}\\right]
 
     
     Parameters