Created FormatProperties (markdown)

FormatProperties.md

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+These functions return properties about known DXGI formats.
+
+```cpp
+bool HasAlpha(DXGI_FORMAT fmt);
+```
+
+```cpp
+size_t BitsPerPixel(DXGI_FORMAT fmt);
+```
+
+```cpp
+size_t BitsPerColorDXGI_FORMAT fmt);
+```
+
+```cpp
+FORMAT_TYPE FormatDataType(DXGI_FORMAT fmt);
+```
+
+# Parameters
+
+These functions all take a ``DXGI_FORMAT`` as their input value.
+
+# Return value
+
+The ``FormatDataType`` function returns ``FORMAT_TYPE_FLOAT``, ``FORMAT_TYPE_UNORM``, ``FORMAT_TYPE_SNORM``, ``FORMAT_TYPE_UINT``, ``FORMAT_TYPE_SINT`` or otherwise ``FORMAT_TYPE_TYPELESS``.