Create PR to demonstrate Docusaurus language and numbered versioning functionality, ability to insert `docs` in URL path as needed

[jhaaaa]

Specifically:

• See how the functionality generates folder structures and URLs. Can it surface the version number in the URL?
• See how the next and current version pattern works
• See how we can use it to create versions that are not sequential numbers (next, current, past), but concurrently valid and supported versions based on programming language. For example, how do we create client SDK doc versions for Javascript and for Swift - both of which are current and supported?
  • Is this a case in which we want to just manually duplicate a folder instead of using the Docusaurus versioning script? YES - this is not versioning - it is just a new doc instance.
• See how we can ensure that all doc content includes a /docs/ segment in the URL

[jhaaaa]

@vehidtr is preparing a POC PR to demonstrate and put up for discussion Docusaurus' ability to generate these types of URL structures:

Versioned docs:

• xmtp.org/docs/client-sdk/javascript/5.0.0
• xmtp.org/docs/client-sdk/javascript/6.0.0
• xmtp.org/docs/client-sdk/javascript/ (current 7.0.0 - but no version in URL per Docusaurus default behavior)
• xmtp.org/docs/client-sdk/javascript/8.0.0-beta (next, custom naming)

Docs that will never be versioned:

• xmtp.org/about/welcome-to-xmtp
• xmtp.org/docs/dev-concepts/security

[jhaaaa]

May be relevant for v2 and v3. Will create a new issue to cover the work, if needed.