[ENGDOCS-1012] Get started update

[craig-osterhout]

Proposed changes

• Clean up some style and formatting
• Change Recap sections to Next steps and add nav buttons
• Rename part 2 'Sample application' topic
• Align TOC with topic names
• Create tabs for codeblocks based on OS
• Restructure part 1 orientation to align with Docker Overview
• Move video and lang-specific to What's Next topic
• Make each command a separate step
• Use the more extensive required dependencies for ARM for all commands to reduce variations

Related issues (optional)

ENGDOCS-1012

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[craig-osterhout]

Closing. Will break apart into smaller PRs.