Readme fix

readme.txt

@@ -6,16 +6,16 @@ example: python main.py -i test_2/products72.grl
          python main.py -o -a test_2/cubes6.grl
 
 mode:
-	Can be -i, -a, or -ia.
-	-i Produces the list of isomorphic pairs of the graphs specified
-	-a Computes the number of automorphisms of the graphs specified
-	-ia Combines -i and -a
+    Can be -i, -a, or -ia.
+        -i Produces the list of isomorphic pairs of the graphs specified
+        -a Computes the number of automorphisms of the graphs specified
+        -ia Combines -i and -a
 
 file:
-	The .grl or .gr file that will be used for the computations
+    The .grl or .gr file that will be used for the computations
 
 -o: (Optional) Optimizes counting isomorphisms by using results of other isomorphic graphs
 
-Alternetively, you can import main in a python shell and call print_isomorphisms or print_automorphisms from there.
+Alternatively, you can import main in a python shell and call print_isomorphisms or print_automorphisms from there.
 
 You can change "from gi import *" to "from fgi import *" in main.py to use fast coloring, which is faster in some cases, and slower in other