Create VSCode extension for LuaLS annotations

[Derpius]

Context

• LuaLS annotations are generated as a single annotations.lua file to the luals-annotations branch
• The LuaLS VSCode extension has support for addons, but the implementation of that isn't great, and doesn't give us the same level of control over our releases as a full VSCode extension
• https://github.com/Derpius/nanosworld-vscode/blob/master/src/extension.ts is an example of this style of extension
• We need to consider how users using older versions of Lest should get documentation
• This extension will eventually implement features like test detection and running (similar to the Jest extension)

Scope

• Update the LuaLS annotations workflow to name/tag each commit with the current Lest version
• Create a new vscode-extension package which is a simple TypeScript Visual Studio Code extension
• For now, just pull the latest annotations.lua to temp storage (see the linked extension above for Nanos World)
• Add the annotations to LuaLS
• Add a workflow to build and release the extension to the marketplace

Acceptance Criteria

• The extension is deployed to the VSCode marketplace on pushes to master
• When the extension is enabled alongside LuaLS, I get annotations for Lest in my source code