clarify compilation requirements in Readme.txt

Readme.txt

@@ -48,6 +48,7 @@ VITA-EXCLUSIVE FEATURES:
 - Savestate with hard-file support: state can be saved even when hard-files are used
 - Additional emulator settings: sprite-sprite collisions can be enabled, blitter settings can be changed
 - Adjustable stereo separation
+- Bluetooth keyboard and mouse support
 
 NOTES:
 
@@ -72,7 +73,7 @@ Selecting a 'Preset Width' of 320, 352 or 384 (max overscan) results in lo-res s
 - Building from Source: The dependencies are
 VitaSDK: http://vitasdk.org (toolchain and Vita system headers etc.)
 SDL_ttf: https://github.com/Cpasjuste/SDL_ttf
-SDL-Vita (v1.2 with 4 controller support): https://github.com/rsn8887/SDL-Vita/tree/SDL12
+SDL-Vita (v1.2 with 4 controller support and with Bluetooth support, from December 24, 2017 or later): https://github.com/rsn8887/SDL-Vita/tree/SDL12
 SDL-Image: https://github.com/Cpasjuste/SDL_image-1.2.12
 Install VitaSDK. Clone all the above repositories and install their libraries using "make -f Makefile.psp2 install" for each one. Cd into a separate build directory outside uae4all2 tree. Type "ccmake <uae4all2 dir>". Then press c (configure). In the release type form field, type "Release" and enter. Then press c then g. Then type "make uae4all2.vpk".