Adding C code and instructions on Redmen

Readme.md

@@ -1,4 +1,24 @@
 # Lecture 4: An overview of C and C++
 A long this lecture let us test two basic Hello World scripts on C and C++, respectively. The idea is to remember the compilation chain process to obtain an executable application.
 
-## C-code 
+## The Hello-Wolrd on C
+The code used for this example is
+```c
+//Gerardo Marx 24/04/2021
+ #include <stdio.h>
+ int main(int argc, char *argv[]){
+ 	printf("Hello World from BeagleBoard!!\n");
+ 	return 0;
+ }
+```
+
+then to compile on an executable code use 
+```bash
+$ gcc hello-world.c -o <output-name>
+```
+here the `<output-name>` is the name that you want for your executable code.
+
+Now it is possible to execute your new code by using:
+```bash
+$ ./<output-name> 
+$ Hello World from BeagleBoard!!