fix: forward missing kwargs from save_as_markdown to export_to_markdown

[nohdonggyeong]

Summary

save_as_markdown() was missing five parameters that exist in export_to_markdown()
and were never forwarded to the internal call.

Fixes #619 (docling-project/docling)

Changes

Added the following parameters to save_as_markdown() and forwarded them to export_to_markdown():

• enable_chart_tables (default: True)
• mark_annotations (default: False)
• traverse_pictures (default: False)
• allowed_meta_names (default: None)
• blocked_meta_names (default: None)

Also addressed the naming inconsistency:

• Added escape_underscores as the canonical parameter name (consistent with export_to_markdown)
• Kept escaping_underscores as a deprecated alias with a DeprecationWarning for backward compatibility

Impact Analysis

save_as_markdown is a wrapper that calls export_to_markdown internally.
The added parameters are simply forwarded — no logic changes, no side effects.
All new parameters have safe defaults matching export_to_markdown behavior,
so existing callers are unaffected.

For escaping_underscores, the deprecated alias path only triggers when
explicitly passed, so backward compatibility is preserved.

Verification

Tested all new parameters against the Docling technical report PDF:

✅ traverse_pictures: OK
✅ allowed_meta_names: OK
✅ blocked_meta_names: OK
✅ enable_chart_tables: OK
✅ mark_annotations: OK
✅ escaping_underscores deprecated alias: OK (warning: 'Parameter `escaping_underscores` is deprecated, use `escape_underscores` instead.')

All cases work as expected. Existing callers are unaffected.

Testing

Existing markdown tests pass.

[github-actions]

❌ DCO Check Failed

Hi @nohdonggyeong, your pull request has failed the Developer Certificate of Origin (DCO) check.

This repository supports remediation commits, so you can fix this without rewriting history — but you must follow the required message format.

---

🛠 Quick Fix: Add a remediation commit

Run this command:

git commit --allow-empty -s -m "DCO Remediation Commit for nohdonggyeong <ehdrud1129@icloud.com>

I, nohdonggyeong <ehdrud1129@icloud.com>, hereby add my Signed-off-by to this commit: eee66996ef02d55eea8b624fdbfb2a2b78966800
I, nohdonggyeong <ehdrud1129@icloud.com>, hereby add my Signed-off-by to this commit: 66d5362c31db0ddd8d6a07092260cca28b3ead6a"
git push

---

🔧 Advanced: Sign off each commit directly

For the latest commit:

git commit --amend --signoff
git push --force-with-lease

For multiple commits:

git rebase --signoff origin/main
git push --force-with-lease

More info: DCO check report

[mergify]

Merge Protections

Your pull request matches the following merge protections and will not be merged until they are valid.

🔴 Require two reviewer for test updates

Waiting for

• #approved-reviews-by >= 2

This rule is failing.

When test data is updated, we require two reviewers

• #approved-reviews-by >= 2

🟢 Enforce conventional commit

Wonderful, this rule succeeded.

Make sure that we follow https://www.conventionalcommits.org/en/v1.0.0/

• title ~= ^(fix|feat|docs|style|refactor|perf|test|build|ci|chore|revert)(?:\(.+\))?(!)?: