Update AStar.js

A* explanation improve spacing.

Author: LindaStern

src/algorithms/pseudocode/AStar.js

@@ -13,7 +13,7 @@ export default parse(`
           initialise, with fontier={s}, stored in Nodes \\Ref Init
             while Nodes not empty \\B 2
             \\Expl{Nodes is the data structure where we store the nodes that are 
-					in the frontier.  In the A* algorithm, Nodes is a Priority Queue.
+		in the frontier.  In the A* algorithm, Nodes is a Priority Queue.
             \\Expl}
             \\In{
                 remove next node n from Nodes and finalise it \\Ref Next_node