[8.x] [Automatic Import] delete readme file

[haetamoudi]

Summary

Manually delete readme.njk file that was missed during backport https://github.com/elastic/kibana/pull/194948 PR in main https://github.com/elastic/kibana/pull/195737 - 8.x

Checklist

• [ ] Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• [ ] Documentation was added for features that require explanation or tutorials
• [ ] Unit or functional tests were updated or added to match the most common scenarios
• [ ] If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the docker list
• [ ] This was checked for breaking HTTP API changes, and any breaking changes have been approved by the breaking-change committee. The release_note:breaking label should be applied in these situations.
• [ ] Flaky Test Runner was used on any tests changed
• [ ] The PR description includes the appropriate Release Notes section, and the correct release_note:* label is applied per the guidelines

[elasticmachine]

Pinging @elastic/security-scalability (Team:Security-Scalability)

[elasticmachine]

:green_heart: Build Succeeded

• Buildkite Build
• Commit: 868b9d60d7a5c9cf80d40538e421681509993b6d

Metrics [docs]

✅ unchanged