Revamp onboarding docs

[neverett]

My goal is to create an updated set of onboarding docs that makes it easier for new users to get started with Flyte. These docs will have the following structure:

• Introduction to Flyte: Getting Started docs landing page
• Quickstart guide: Quick intro to creating and running a workflow
• Getting started with Flyte development: New section to hold the pages below
  • Index page
  • Installing development tools
  • Creating a Flyte Project
  • Flyte project components
  • Running Flyte workflows and tasks locally

TODO

Before merging this PR

• Merge Add images of flyte console for onboarding docs revamp static-resources#31
• Update image links in running_a_workflow_locally.md to point to main branch of static-resources repo
• Merge Add basic template that uses ImageSpec flytekit-python-template#43 to add a new ImageSpec-based flytekit template
• Merge Update default template used by pyflyte init flytekit#2041 to update flytekit to use the new basic ImageSpec template by default for pyflyte init
• Add redirect for "Creating a Flyte project" (old file: creating_flyte_project.md, new file: creating_a_flyte_project.md)
• Add redirect for "Visualizing artifacts"

After merging this PR

• Close [Docs] De-emphasize Docker. Explain that any OCI container daemon will work. flyte#3243
• Close [Docs] Mention need to create an initial git commit flyte#3520
• Merge Updates for onboarding docs revamp flyte#4548