[Automatic Import] add fields mapping to readme

[haetamoudi]

Summary

Duplicate of #193334

Automatic import flow creates 2 Readme files:

• Content of docs/README.md will contain the mapping fields for each datastream and will be used to show information when opening a newly created integration.
• Content of _dev/build/docs/README.md will contain a placeholder that can be replaced when using elastic-package.

Test results:

Use Automatic import to create a new integration.

docs/README.md

That will be displayed like:

_dev/build/docs/README.md

[elasticmachine]

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

[ilyannn]

Good work, but I think we should strive to make the two readmes have the same relationship as if the user actually ran the elastic-package build. There are currently some differences, which I've checked by downloading a generated package and running

git init
git add .
git commit -m "Generated version"
elastic-package build
git diff > diff.txt

Here's an example diff.txt. I think the differences are mostly in the whitespace, default value and the additional files, such as base-fields.yml.

If it's not too hard to replicate what the elastic-package does, let's try to kill this diff.

[ilyannn]

I had some points to address.

The goal to replicate elastic-package isn't absolute, so let's skip it if it proves too hard.

[ilyannn]

Looks good, though I have not tested it yet.

We might want to think about the actual content of the README (generate with LLM?)

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: c58a58f

Failed CI Steps

• FTR Configs #1

Test Failures

• [job] [logs] FTR Configs #1 / Cloud Security Posture Test adding Cloud Security Posture Integrations CNVM CNVM AWS Hyperlink on PostInstallation Modal should have the correct URL

Metrics [docs]

✅ unchanged

History

• 💛 Build #237417 was flaky fce0935
• 💛 Build #236624 was flaky ec0197c
• 💛 Build #236563 was flaky 9a14b60
• 💛 Build #236404 was flaky 184e334
• 💔 Build #236378 failed 7d781d5

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @haetamoudi

[kibanamachine]

Starting backport for target branches: 8.x

https://github.com/elastic/kibana/actions/runs/11272440817

[kibanamachine]

Starting backport for target branches: 8.x

https://github.com/elastic/kibana/actions/runs/11272440702

[kibanamachine]

💔 All backports failed

Status	Branch	Result
❌	8.x	Backport failed because of merge conflicts

Manual backport

To create the backport manually run:

node scripts/backport --pr 193717

Questions ?

Please refer to the Backport tool documentation

[kibanamachine]

💔 All backports failed

Status	Branch	Result
❌	8.x	Backport failed because of merge conflicts

Manual backport

To create the backport manually run:

node scripts/backport --pr 193717

Questions ?

Please refer to the Backport tool documentation

[bhapas]

💚 All backports created successfully

Status	Branch	Result
✅	8.x

Note: Successful backport PRs will be merged automatically after passing CI.

Questions ?

Please refer to the Backport tool documentation