Wrote info in readme.txt

examples/example_4/readme.txt

@@ -1,5 +1,14 @@
-Example 1
+Example 4
 =========
 
 Close to the simplest possible example of Unity, using only basic features.
-Run make to build & run the example tests.
+to build this example run meson setup <build dir name>.
+
+Meson uses the Ninja build system to actually build the code. To start the 
+build, simply type the following command.  
+
+"ninja -C <build dir name>"
+
+Meson provides native support for running tests. The command to do that is simple.
+
+"meson test -C <build dir name>".