Add headers to install cmake (#1462)

* Changed extension for web from .bc to .a

I did this to support vcpkg expectation. When using the library from vcpkg for web you would install it using vcpkg install raylib:wasm32-emscripten but also vcpkg expects the output lib to be with .a extension instead of .bc

Doesn't make a difference for standalone builds or when raylib is used as a subdirectory dependency.

* Added headers to install targets to fix vcpkg usage

Currently vcpkg works by installing the cmake target into its packages directory. The problem is that install only copies the public header at this point so we need to add the others to the install targets.

src/CMakeLists.txt

@@ -207,7 +207,7 @@ if(STATIC)
       ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}"
       PUBLIC_HEADER DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
   )
-set_target_properties(raylib_static PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_BINARY_DIR}")
+  set_target_properties(raylib_static PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_BINARY_DIR}")
 
   add_test("pkg-config--static" ${PROJECT_SOURCE_DIR}/../cmake/test-pkgconfig.sh --static)
 endif(STATIC)
@@ -292,6 +292,13 @@ file(COPY "physac.h" DESTINATION ".")
 file(COPY "raymath.h" DESTINATION ".")
 file(COPY "raudio.h" DESTINATION ".")
 
+# Also install them
+install(FILES "raylib.h" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+install(FILES "rlgl.h" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+install(FILES "physac.h" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+install(FILES "raymath.h" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+install(FILES "raudio.h" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+
 # Print the flags for the user
 if (DEFINED CMAKE_BUILD_TYPE)
   message(STATUS "Generated build type: ${CMAKE_BUILD_TYPE}")