DOC fix display of Haversine equation (scikit-learn#10403)

Author: pinakinathc

sklearn/neighbors/dist_metrics.pyx

@@ -141,12 +141,11 @@ cdef class DistanceMetric:
     distance metric requires data in the form of [latitude, longitude] and both
     inputs and outputs are in units of radians.
 
-    ============  ==================  ========================================
+    ============  ==================  ===============================================================
     identifier    class name          distance function
-    ------------  ------------------  ----------------------------------------
-    "haversine"   HaversineDistance   2 arcsin(sqrt(sin^2(0.5*dx)
-                                             + cos(x1)cos(x2)sin^2(0.5*dy)))
-    ============  ==================  ========================================
+    ------------  ------------------  ---------------------------------------------------------------
+    "haversine"   HaversineDistance   ``2 arcsin(sqrt(sin^2(0.5*dx) + cos(x1)cos(x2)sin^2(0.5*dy)))``
+    ============  ==================  ===============================================================
 
 
     **Metrics intended for integer-valued vector spaces:**  Though intended