Docs: add more links to the top of every examples and backends files.

examples/example_sdl2_vulkan/main.cpp

@@ -1,6 +1,10 @@
 // Dear ImGui: standalone example application for SDL2 + Vulkan
-// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
-// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// Learn about Dear ImGui:
+// - FAQ                  https://dearimgui.com/faq
+// - Getting Started      https://dearimgui.com/getting-started
+// - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
+// - Introduction, links and more at the top of imgui.cpp
 
 // Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
 // - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.