Add Classic token filter docs

[AntonEliatra]

Description

Add Classic token filter docs

Issues Resolved

Closes https://github.com/opensearch-project/documentation-website/issues/7876

Version

all

Checklist

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

[github-actions[bot]]

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[kolchfa-aws]

@udabhas Could you review this PR for technical accuracy?

[vagimeli]

@varun-lodaya The documentation is awaiting tech review and approval, which is delaying progress. Could you please suggest alternative reviewers who can assist with this task in a timely manner? We're eager to move this forward. Thank you.

[vagimeli]

@AntonEliatra Please see the tech reviewer's feedback. Thank you.

[vagimeli]

@AntonEliatra Thanks for address tech comments. Moving this forward for doc review with @kolchfa-aws.