Vertex Loading

Added the ability to load vertex data from the WAD. Still needs
some processing to make more robust, but for now is loading data.

src/types/mod.rs

@@ -0,0 +1,3 @@
+mod vertex;
+
+pub use vertex::Vertex;

src/types/vertex.rs

@@ -0,0 +1,5 @@
+#[derive(Clone, Debug, PartialEq)]
+pub struct Vertex {
+    pub x: i16,
+    pub y: i16,
+}