COMP/CON Content Authoring extension for VSCode

This simple extension right now does two things:

• Adds JSON schemas for C/C content pack .json files (lcp_manifest.json, weapons.json, etc...)
• Adds a build task that generates the .LCP file at workspace root. For the task to work, you need in your PATH: 7zip CLI on windows (7z), or zip on mac/linux (NOTE: latter two not actually tested)