Update community resource links

(cherry picked from commit d7ae90a790416f150a39e8f42f8278598bafae29)

docs/build.dox

@@ -225,6 +225,9 @@ library and include directory paths.  Link against this like any other library.
 target_link_libraries(myapp OpenGL::GL)
 @endcode
 
+For a minimal example of a program and GLFW sources built with CMake, see the
+[GLFW CMake Starter](https://github.com/juliettef/GLFW-CMake-starter) on GitHub.
+
 
 @subsection build_link_cmake_package With CMake and installed GLFW binaries
 

docs/quick.dox

@@ -246,12 +246,16 @@ glViewport(0, 0, width, height);
 You can also set a framebuffer size callback using @ref
 glfwSetFramebufferSizeCallback and be notified when the size changes.
 
-Actual rendering with OpenGL is outside the scope of this tutorial, but there
-are [many](https://open.gl/) [excellent](https://learnopengl.com/)
-[tutorial](http://openglbook.com/) [sites](http://ogldev.atspace.co.uk/) that
-teach modern OpenGL.  Some of them use GLFW to create the context and window
-while others use GLUT or SDL, but remember that OpenGL itself always works the
-same.
+The details of how to render with OpenGL is outside the scope of this tutorial,
+but there are many excellent resources for learning modern OpenGL.  Here are
+a few of them:
+
+ - [Anton's OpenGL 4 Tutorials](https://antongerdelan.net/opengl/)
+ - [Learn OpenGL](https://learnopengl.com/)
+ - [Open.GL](https://open.gl/)
+
+These all happen to use GLFW, but OpenGL itself works the same whatever API you
+use to create the window and context.
 
 
 @subsection quick_timer Reading the timer

docs/vulkan.dox

@@ -4,8 +4,8 @@
 
 @tableofcontents
 
-This guide is intended to fill the gaps between the [Vulkan
-documentation](https://www.khronos.org/vulkan/) and the rest of the GLFW
+This guide is intended to fill the gaps between the official [Vulkan
+resources](https://www.khronos.org/vulkan/) and the rest of the GLFW
 documentation and is not a replacement for either.  It assumes some familiarity
 with Vulkan concepts like loaders, devices, queues and surfaces and leaves it to
 the Vulkan documentation to explain the details of Vulkan functions.
@@ -14,6 +14,11 @@ To develop for Vulkan you should download the [LunarG Vulkan
 SDK](https://vulkan.lunarg.com/) for your platform.  Apart from headers and link
 libraries, they also provide the validation layers necessary for development.
 
+The [Vulkan Tutorial](https://vulkan-tutorial.com/) has more information on how
+to use GLFW and Vulkan.  The [Khronos Vulkan
+Samples](https://github.com/KhronosGroup/Vulkan-Samples) also use GLFW, although
+with a small framework in between.
+
 For details on a specific Vulkan support function, see the @ref vulkan.  There
 are also guides for the other areas of the GLFW API.