Move official docs page to this repo and update accordingly

Currently, there are 2 sets of docs for this library:

• docs hosted on https://plotly.net, which i will call internal in this issue:

  • built in this repo using fsdocs
  • contains tutorials rendered from .fsx files and api docs created by fsdocs via assembly inspection
  • are up-to-date with the currently version of the library
  • almost exclusively F# content (meaning C# users need to put in a little effort translating the code samples)

• docs hosted on https://plotly.com/fsharp and https://plotly.com/csharp , which i will call official in this issue

  • built with the behemoth docs build pipeline of plotly, which i currently have absolutely no idea how it works, other than that they most likely use the content of https://github.com/plotly/plotly.net-docs. https://github.com/plotly/documentation/issues/1696 might help here eventually
  • contains (incomplete) translations of the python tutorials hosted on https://plotly.com/python
  • are severely out-of-date (using a preview version of 2.0.0)
  • can host both F# and C# content

There is understandably quite some confusion about this (see #353 and #356), with users coming from the official docs reporting issues that are long fixed in recent versions. In addition to that, providing high-quality C# docs is hard with fsdocs, which mainly focuses on creating F# content with F# tooling.

Since official docs most likely have way better SEO than the internal one, this problem will only increase with time, meaning we should move to only hosting the official docs.

So the following should be done imo:

• change the doc build pipeline to use content in this repo instead of https://github.com/plotly/plotly.net-docs, since i do not want to maintain two separate repos for this. Python , JS, and R versions of plotly do it that way as well.
• use the api docs output from fsdocs, similarily to what the python lib is doing
• ditch fsdocs for the tutorials in favor of the official docs build pipeline.

Start by comparing the current fsdocs setup in this repository with the official content and pipeline in plotly.net-docs, and review documentation/issues/1696 plus issues #353 and #356 for constraints. Done means the official pipeline consumes tutorial content from this repo, publishes fsdocs-generated API docs, and no longer relies on a separate tutorials repository or fsdocs tutorial build.