Add April 2025 flights to flight tests doc

[Elan456]

Description

Adds April flights to the Avionics documentation

Summary of Changes

• Adds 3 launches to the flight tests (AA-AA-04-13-2025-0, AA-MA-04-13-2025-0, L1-MA-04-12-2025-0)
• Moves flight tests to a separate markdown file
• Updates the README with the new data saver and state estimation tools.

Motivation

• Important to keep our documentation up to date

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Testing

Check all that apply:

• I have added or modified tests to cover these changes.
• I have manually tested the changes on the target device(s) or environment(s).
• Existing tests were reviewed to ensure they still work as expected.
• If tests were not added or modified, explain why:

  Only markdown files were changed

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Building

• This change successfully builds in at least one of the following environments:
  • Native repo
  • Target device(s) (e.g., MARTHA)
• If the build fails in any environment, explain why:

  (Provide reasoning here)

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Checklist

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code where necessary for clarity.
• I have made corresponding updates to documentation (if applicable).

[mcschoo]

Nothing to add

[mcschoo]

You could add the point of CommunicateVerification showing deployment on the pad, but that's a little niche, so up to you