Updated INSTALL.md with simple intro breadcrumbs

README.md

@@ -6,8 +6,11 @@ and emulators.
 You can find the latest release and additional documentation at:
 https://www.libsdl.org/
 
+Installation instructions and a quick introduction is available in
+[INSTALL.md](INSTALL.md)
+
 This library is distributed under the terms of the zlib license,
-available in the file LICENSE.txt.
+available in [LICENSE.txt](LICENSE.txt).
 
 Enjoy!