Chore: Website Versioning Scripts

[bbazukun123]

Resolves ticket.

Quick explainers:

• The term snapshot here refers to a version of the docs that was copied and preserved within the versioned_docs directory by Docusaurus. (Ref: https://docusaurus.io/docs/versioning)
• For better alignment, metadata from pixi-version.json within the docs directory is being used to determine the version number and label.
• Instead of manually managing our pixi-version.json configs, Docusaurus' versions.json, Docusaurus' versioned directory and sidebar namings, and the global configs likepixi-versions.json and the version section on docusaurus.config.js, utility scripts were implemented to simplify the workflow and make it interactive where applicable.
• ** Please note that these scripts are subjected to rapid changes while we are solidifying our website workflow **

Changelog:

• Update generate-pixi-version-config script to prevent from creating a version config of an existing docs snapshot.
• Add create-docs-version-snapshot script that creates a new Docusaurus docs version based on the pixi-version.json available on the working docs.
• Add remove-docs-version-snapshot script that removes an existing instance of versioned docs, its versioned sidebar and removes its version number from the versions.json.
• Add update-global-version-configs script that aligns pixi-versions.json and docusaurus.config.js to the current state of the versions.
• Add update-pixi-version-configs scripts that fetches up-to-date versions and tags of PixiJS and use them to update the pixi-version.json configs, if outdated (ie. the version label, the latest flag, etc.).