Added README.md

README.md

src/Graph_Generator.c

src/HelloWorld.c

src/MPI_HelloWorld.c

src/MST_OpenMP

src/MST_OpenMP.c

src/MST_Serial

src/MST_Serial.c

test/test_10

test/test_100

test/test_1000

test/test_20

test/test_200

test/test_30

test/test_300

test/test_40

test/test_5

test/test_50

test/test_500