Add app details to README

README.md

@@ -4,6 +4,18 @@ POSIX libmpix example
 An example application that runs on any reasonably POSIX system, such as Linux, BSD, Mac OS, as
 well as some RTOS.
 
+The application does the following
+- Initializes a buffer with some pixel data and uses that buffer to build an image
+- Prints this image out to console
+- It then applies a number of format conversions to the image 
+- Fills an output buffer with the the converted image
+
+
+Note: 
+On some systems you may run into a missing python issues, usually one needs to install python or symlink
+a specific version of python such as `python3` to python.
+
+
 ```sh
 export LIBMPIX="$PWD/libmpix"
 

main.c

@@ -39,6 +39,7 @@ int main(void)
 		return img.err;
 	}
 
+	mpix_image_from_buf(&img, buf_out, sizeof(buf_out), APP_WIDTH, APP_HEIGHT, APP_FOURCC);
 	mpix_image_print_truecolor(&img);
 
 	return 0;