Updated Installing TFT_eSPI on PlatformIO (markdown)

Installing-TFT_eSPI-on-PlatformIO.md

@@ -25,8 +25,16 @@ We can achieve this by using PlatformIO's [`build_flags`](https://docs.platformi
 - First of all we prevent user settings headers to be loaded by defining `USER_SETUP_LOADED`.
 - Next include the User_SetupXX_XXXX.h file that maches your configuration.
 Your code now looks like this:
+```INI
+build_flags =
+  ;###############################################################
+  ; TFT_eSPI library setting here (no need to edit library files):
+  ;###############################################################
+  -D USER_SETUP_LOADED=1                        ; Set this settings as valid
+  -include $PROJECT_LIBDEPS_DIR/$PIOENV/TFT_eSPI_ID1559/User_Setups/Setup1_ILI9341.h
+```
 
-### 4. Include header
+### 5. Include header
 Add the line `#include <TFT_eSPI.h>`at the top of your files.
 
 Enjoy! ;)