Small cleanups and doc updates

Author: dibyendumajumdar

optvm/README.md

@@ -42,9 +42,9 @@ a physical machine. Therefore, all our optimization passes will work on the inst
 * [InterferenceGraphBuilder](src/main/java/com/compilerprogramming/ezlang/compiler/InterferenceGraphBuilder.java) - Constructs an InterferenceGraph for a set
   of basic bocks, using basic block level liveness information as a starting point for calculating instruction level liveness.
 * [ChaitinGraphColoringRegisterAllocator](src/main/java/com/compilerprogramming/ezlang/compiler/ChaitinGraphColoringRegisterAllocator.java) - basic
-  Chaitin Graph Coloring Register Allocator. Since our target machine here is an abstract machine, we do mot really needing spilling support
+  Chaitin Graph Coloring Register Allocator. Since our target machine here is an abstract machine, we do not really needing spilling support
   as we can size each function's stack frame to accommodate the number of registers needed such that each register is really a slot in the stack
-  frame. But we will eventually simulate an abstract machine with a limited set of registers and a stack frame.
+  frame. But we will eventually simulate an abstract machine with a limited set of registers and a separate stack frame.
 
 ## Compiler