Add basic overview of the API basics.

notes.md

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+`VkInstance` - application and extensions
+ - `VkPhysicalDevice` - selected based on properties and capabilities
+
+ - `VkDevice` (also known as a logical device), describes which `VkPhysicalDeviceFeatures` will be used, which queue families
+  - `VkQueue`, allocated from queue families, examples of families are graphics, compute, and memory transfer
+
+ - `VkSurfaceKHR`, a window surface, it's an extension that provides ways to interact with the window manager,
+   in our case GLFW will handle the specific details.
+
+ - `VkSwapchainKHR`, a swap chain, it's a collection of targets for rendering. its first purpose is ensuring that the image
+   that is being rendered is not the same one that is on the screen, the most common ways to use one are double and triple
+   buffering, swapchains provide images.
+
+ - On some platforms there are extensions (`VK_KHR_display`, `VK_KHR_display_swapchain`) that allow one to draw to the entire
+   screen.
+
+ - Once an image is obtained from the swapchain it has to be wrapped into:
+   - `VkImageView`, an image view references a specific part of an image to be used
+   - `VkFramebuffer`, a framebuffer references images that are used for color, depth, and stencil targets.
+     in these examples the image views and framebuffers for each image in the swapchain will be created
+     ahead of time.
+
+ - Render passes describe the type of images that are used during rendering, their usage, and how their
+   content will be treated, to draw a simple triangle we can tell vulkan that there will be a single image
+   that's a color target and that it needs to be cleared to a solid color before drawing.
+   Note: a render pass describes the type of images, a `VkFramebuffer` binds specific images to slots.
+
+ - `VkPipeline`, describes the configuration of the graphics card, like viewport size, depth buffer operations,
+   the programmable state is specified using `VkShaderModule` objects, which are created from shader bytecode.
+   The driver also needs to know which render targets are going to be used in the pipeline.
+   All of the settings are configured in advance, and changing them requires creating a new `VkPipeline`.
+
+ - Commands are recorded into a `VkCommandBuffer`, the buffers are allocated out of a `VkCommandPool` associated
+   with a queue family, in order to do some simple drawing we need to do the following:
+   - being a pass
+   - bind the pipeline
+   - draw 3 vertices
+   - end the pass
+   Since the image depends on which specific image the swap chain is going to give us, a command buffer for each
+   possible image will have to be recorded and the right one will be selected at draw time.
+   Recording every frame is also an option but it would be less performant.
+
+ - Application main loop
+  - acquire image via `vkAcquireNextImageKHR`
+  - `vkAcquireNextImageKHR` to acquire an image
+  - select appropriate command buffer for the image
+  - execute the command buffer with `vkQueueSubmit`
+  - return the image to the swapchain for presentation with `vkQueuePresentKHR`
+