add sample templates for text to visualziation

[ruanyl]

Description

Add sample templates for text to visualization.
These templates will be used by OpenSearch-Dashboards plugin dashboards-assistant to setup text to visualization feature. Documentation could be found here: https://opensearch.org/docs/latest/dashboards/dashboards-assistant/text-to-visualization/

Related Issues

Resolves #[Issue number to be closed when this PR is merged]

Check List

• New functionality includes testing.
• New functionality has been documented.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[ruanyl]

@dbwiddis @owaiskazi19 Could you take a look the PR please?

[dbwiddis]

@ruanyl Will do. I saw it earlier but it was in draft until just now.

Note the spotless check is failing (looks like trailing whitespace). Please run ./gradlew spotlessApply and commit the difference. Also add a section to the 2.x documentation on the change log.

[dbwiddis]

LGTM pending spotless fix

[owaiskazi19]

@ruanyl can you also some description about the use case for this template in the PR?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.57%. Comparing base (9b9ebb2) to head (de6cae1).
Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #936      +/-   ##
============================================
- Coverage     78.07%   77.57%   -0.50%     
+ Complexity      996      993       -3     
============================================
  Files            99       99              
  Lines          4625     4714      +89     
  Branches        431      431              
============================================
+ Hits           3611     3657      +46     
- Misses          834      877      +43     
  Partials        180      180              

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[yuye-aws]

@ruanyl can you also some description about the use case for this template in the PR?

Description updated. Can u review again?

[yuye-aws]

@ruanyl Is there going to be a PR adding t2vega_agent (without instruction)?