fix numbering in local tractography

_episodes/local_tractography.md

@@ -19,7 +19,7 @@ keypoints:
 
 Local tractography algorithms follow 2 general principles:
 1. Estimate the fiber orientation, and
-1. Follow along these orientations to generate/propagate the streamline.
+2. Follow along these orientations to generate/propagate the streamline.
 
 Streamline propagation is, in essence, a numerical analysis integration
 problem. The problem lies in finding a curve that joins a set of discrete local
@@ -34,8 +34,8 @@ To perform conventional local fiber tracking, three things are needed beyond the
 propagation method itself:
 1. A method for getting local orientation directions from a diffusion MRI
   dataset (e.g. diffusion tensor).
-1. A set of seeds from which to begin tracking.
-1. A method for identifying when to stop tracking.
+2. A set of seeds from which to begin tracking.
+3. A method for identifying when to stop tracking.
 
 Different alternatives have been proposed for each step depending on the
 available data or computed features.