Move doc.Doc to tfconf.Module

[khos2ow]

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Description

This PR refactors the confusing doc.Doc to tfconf.Module for better readability and also adjusts sorting and references with pointers for better performance.

Issues Resolved

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Checklist

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• I have read the Contributing Guidelines.

Tests

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• All tests pass when I run make test.

Documentation

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• I have updated the documentation accordingly.

Code Style

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