SteamKit VPK

This crate is a simple library to help parse and read files based on the VPK file format.

To-do

• Remove the CS:GO & Portal 2 dir assets (even though they mostly only describe the rest of the pack).
• Add some generated/custom packs for testing reading and value checking.
• Add a test for reading data from preload.
• Add a test for reading from data section.
• Add a test for reading from a separate archive-part.
• Optimize the tree parser (with capacity hints).