feat: update index and beta pages

[cfu288]

Opening a draft PR for proposed changes as part of the re-organization of the docs repo.

I think the first three pages to the docs site should be the following:

1. Welcome - Intro, explain what Fasten is, give user actionable next steps
2. What can Fasten do? - List and demo of current features
3. Getting started with Fasten - Installation instructions for the Fasten beta

Current tasks:

• Improve welcome/index page with gentler onboarding and actionable buttons to guide users to next steps
• Add a "What can fasten do?" page with a quick overview of Fasten in its current state with videos/pictures.
• Update the beta page to a "Getting started" page with guided installation instructions

[AnalogJ]

This is a fantastic start, thanks @cfu288 !

[AnalogJ]

Hey @cfu288 this looks pretty good, other than a couple of small nits. However its still in Draft, should I mark it ready for review and merge it? Or do you have plans to make more changes?

[cfu288]

@AnalogJ Ah, in my mind its a WIP since I was planning on adding a bit more before merge and proofreading. If you're happy with it we can merge it now and I'll make another PR with the "What can fasten do?" feature demo page.

[AnalogJ]

yeah, I lean towards making small PR's without long lived branches. I plan on making some changes to the docs repo myself as well, and I don't want to introduce any conflicts with your work.

[cfu288]

Fair enough, I'm done with changes for now - just pushed some last minute typo fixes

[AnalogJ]

awesome, I merged your changes and they should be visible on docs.fastenhealth.com in a couple minutes.

I'll also add some info to the pre-v0.1.9 release notes issue