Updated build text

Author: rijnb

README.md

@@ -48,12 +48,12 @@ of how to use the library.
 
 To build the original Mapcode tool, execute:
 
-  cd utility
-  gcc -O mapcode.cpp -o mapcode
+    cd utility
+    gcc -O mapcode.cpp -o mapcode
 
 (Or if you need to make sure there are no warnings:)
 
-  gcc -Wall -Wstrict-prototypes -Wshorten-64-to-32 -O mapcode.cpp -o mapcode
+    gcc -Wall -Wstrict-prototypes -Wshorten-64-to-32 -O mapcode.cpp -o mapcode
 
 For help, simply execute the binary file 'mapcode' without no arguments.
 This tool provides a rather extensive command-line interface to encode and