Adds Structure collection documentation and examples.

docs/collections/structure.md

@@ -1 +1,28 @@
-# Byteclasses Structure Collection
+# Structure
+
+A Structure is a dynamic byteclass created using the `@structure` decorator.
+
+```python
+@structure
+class MyStructure:
+    """My Structure Byteclass."""
+
+    var1: UInt64 = UInt64()
+    var2: UInt32 = UInt32()
+```
+
+Similar to a C `struct`, each member of a byteclass `structure` has a sequential offset. By default, `structure` are padded so each member is size aligned. The `structure` decorator accepts a boolean `padding` parameter to override the default padding behavior.
+
+The length of a Structure byteclass is determined when the class is created based on its members.
+
+A Structure byteclass can contain both byteclass primitives and other byteclass collections.
+
+Each Structure member has its own `byte_order`. However, the `structure` decorator accepts a `byte_order` parameter which is used for any members that rely on a `default_factory` for instantiation.
+
+```python
+@structure(byte_order=b">")
+class FactoryStructure:
+    """A structure byteclass with member using default factory."""
+
+    a: UInt64 = member(default_factory=UInt64)
+```