chore: Add badges to readme

[thompson-tomo]

This adds the ossf scorecard badge to the readme to improve the clo monitor score and make it easily accessible to those interested.

Can a maintainer register this repo on https://www.bestpractices.dev/en/projects?q=Opentelemetry & we can add that badge as part of this PR.

Also added is the fossa badges & best practices badge which also improves the clo monitor score.

[welcome]

Thanks for opening your first pull request! If you haven't yet signed our Contributor License Agreement (CLA), then please do so that we can accept your contribution. A link should appear shortly in this PR if you have not already signed one.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 68.40%. Comparing base (606ec77) to head (571e189).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1804      +/-   ##
============================================
- Coverage     68.49%   68.40%   -0.10%     
  Complexity     2974     2974              
============================================
  Files           448      448              
  Lines          8722     8722              
============================================
- Hits           5974     5966       -8     
- Misses         2748     2756       +8     

Flag	Coverage Δ
8.1	68.16% <ø> (+<0.01%)	⬆️
8.2	68.33% <ø> (-0.05%)	⬇️
8.3	68.34% <ø> (+0.03%)	⬆️
8.4	68.33% <ø> (+<0.01%)	⬆️
8.5	67.51% <ø> (-0.02%)	⬇️

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see 5 files with indirect coverage changes

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[brettmc]

Can a maintainer register this repo on https://www.bestpractices.dev/en/projects?q=Opentelemetry & we can add that badge as part of this PR.

https://www.bestpractices.dev/en/projects/11534

[thompson-tomo]

Thanks @brettmc have added the corresponding badge for clo monitor etc.

[trask]

@thompson-tomo please create an issue in https://github.com/open-telemetry/sig-security to discuss first before sending these PRs so we can agree on a plan and we can then link these PRs to that plan in order to provide more context to maintainers. Thanks!