Chore: Website Restructuring

[bbazukun123]

Resolves ticket.

• Move tutorial and playground sections into the main Docusaurus docs structure to allow it to take the effect of nav's version control.
• Swizzle out the Footer component and adjust it so that it does not render for the pages above.
• Move tutorial content into src as its own source directory, reflecting that of the examples.
• Add PixiJS version config to the docs directory that will reflect the version being used on the playgrounds, including the versioned ones in the future.
• Add pixi version config generation script to help with the creation or modification of the config.
• Add versioning to the examples and tutorials source directories, matching the PixiJS version configs being used.
• Add tutorial docs generation script.
• Update example docs generation script.