Update README

Author: andypugh

tests/spindle_limits/README

@@ -1,9 +1,11 @@
 Test that the spindle speed limits from the INI are honoured. 
-Tests three spindles, to ensure that multi=spindle is supported
+Tests three spindles, to ensure that multi-spindle is supported
+
 Spindle.0 has limits for MAX_FORWARD, MIN_FORWARD, MAX_REVERSE and MIN_REVERSE
 Spindle.1 has no MIN_REVERSE to test that MIN_FORWARD is applied in reverse
-Spindle.2 has no reverselimits, to test that both forwards limits are tested in reverse
-Spindle commands through bith G-code (via MDI) and Python interface are tested. 
+Spindle.2 has no MIN_REVERSE or MAX_REVERSE to test that both *_FORWARD limits are applied in reverse
+
+Spindle commands through both G-code (via MDI) and Python interface are tested. 
 
 FIXME (?)
 spindle commands through halui are not tested