Update README.md

README.md

 # MPI LAB
 
+*topics*
+* Prepare Environment
+    * Running an MPI cluster within a LAN
+    * Running an MPI hello world application
+* Blocking point-to-point communication
+    * Sending and receiving with MPI_Send and MPI_Recv
+
 ## Prepare your User
 To establish ssh connection between master and slaves without prompt required password we copy
 public id on slave machines as following
@@ -37,3 +44,5 @@ mpirun -np 3 -f mpi_hosts ./mpi_sampl
 ```
 
 
+*Useful Links*
+* [MPI Tutorial](https://mpitutorial.com/tutorials/)
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