Update 'README.md'

README.md

@@ -1,4 +1,5 @@
-g++ -std=c++11 -Wall -Wextra -Werror server.cpp -lpthread
+```g++ -std=c++11 -Wall -Wextra -Werror server.cpp -lpthread```
 
-brew install asio
+```brew install asio```
-brew install boost
+
+```brew install boost```