Use designated initializers and use explicit array types

[johannes-el]

Refactored descriptor setup to use explicit array initialization and designated initializers.
Should I apply the same designated-initializer and explicit-type style to the C++ side as well, or leave it as-is to avoid potential merge conflicts?

[asuessenbach]

You could as well go one step further with designated initializers, like

    std::array<vk::DescriptorSetLayoutBinding, 2> bindings = {
      { { .binding = 0, .descriptorType = vk::DescriptorType::eUniformBuffer, .descriptorCount = 1, .stageFlags = vk::ShaderStageFlagBits::eVertex },
        { .binding = 1, .descriptorType = vk::DescriptorType::eCombinedImageSampler, .descriptorCount = 1, .stageFlags = vk::ShaderStageFlagBits::eFragment } }
    };

[SaschaWillems]

It's one of those areas where the tutorial is lacking consistency. We prob. should discuss this on our next call and agree on how we want to write code and then start updating the documentation accordingly.