doc: add mcp doc for embedder model

[liangyuanpeng]

I'm using mcp with custom embedder module and since there was no documentation, it took me some time. I think adding this instruction would be very useful.

Summary

Brief description of the changes in this PR.

Type of Change

• Bug fix
• New feature
• Performance improvement
• Documentation/Tests

Objective

For new features and performance improvements: Clearly describe the objective and rationale for this change.

Testing

• Unit tests added/updated
• Integration tests added/updated
• All existing tests pass

Breaking Changes

• This PR contains breaking changes

If this is a breaking change, describe:

• What functionality is affected
• Migration path for existing users

Checklist

• Code follows project style guidelines (make lint passes)
• Self-review completed
• Documentation updated where necessary
• No secrets or sensitive information committed

Related Issues

Closes #[issue number]

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Important

Add documentation for configuring custom embedder models in MCP server by introducing EMBEDDER_MODEL_NAME in README.md and .env.example.

• Documentation:
  • Adds EMBEDDER_MODEL_NAME to README.md and .env.example for configuring custom embedder models.
  • Provides instructions for setting EMBEDDER_MODEL_NAME for embedding operations in README.md.

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[danielchalef]

All contributors have signed the CLA ✍️ ✅
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[ellipsis-dev]

Important

Looks good to me! 👍

Reviewed everything up to 6530341 in 42 seconds. Click for details.

• Reviewed 26 lines of code in 2 files
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1. mcp_server/.env.example:14

• Draft comment:
  Good addition for embedder configuration. Consider adding a note that this variable is commented out by default and must be uncommented to take effect.
• Reason this comment was not posted:
  Confidence changes required: 33% <= threshold 80% None

2. mcp_server/README.md:94

• Draft comment:
  Nice documentation update. For clarity, consider adding a brief example of how to set EMBEDDER_MODEL_NAME in a .env file.
• Reason this comment was not posted:
  Confidence changes required: 33% <= threshold 80% None

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[liangyuanpeng]

I have read the CLA Document and I hereby sign the CLA