Update to SDL 2.30.5

SDL2-2.30.5/INSTALL.txt

@@ -0,0 +1,41 @@
+
+To compile and install SDL:
+
+    1.  Windows with Visual Studio:
+        * Read ./docs/README-visualc.md
+
+        Windows with gcc, either native or cross-compiling:
+        * Read the FAQ at https://wiki.libsdl.org/FAQWindows
+        * Run './configure; make; make install'
+
+        macOS with Xcode:
+        * Read docs/README-macosx.md
+
+        macOS from the command line:
+        * Run './configure; make; make install'
+
+        Linux and other UNIX systems:
+        * Run './configure; make; make install'
+
+        Android:
+        * Read docs/README-android.md
+
+        iOS:
+        * Read docs/README-ios.md
+
+        Using Cmake:
+        * Read docs/README-cmake.md
+
+    2.  Look at the example programs in ./test, and check out the online
+        documentation at https://wiki.libsdl.org/
+
+    3.  Join the SDL developer discussions, sign up on 
+        https://discourse.libsdl.org/
+        and go to the development forum
+        https://discourse.libsdl.org/c/sdl-development/6
+
+    4.  Sign up for the announcement list through the web interface:
+        https://www.libsdl.org/mailing-list.php
+
+That's it!
+Sam Lantinga <slouken@libsdl.org>