feat: support sync docs from multiple PRs

[Oreoxmt]

Close #18
Test result:

Running Tests...
100%|█████████████████████████████████████████████████████████████████████████████████████| 1/1 [00:24<00:00, 24.74s/it]
100%|█████████████████████████████████████████████████████████████████████████████████████| 4/4 [03:46<00:00, 56.56s/it]
100%|████████████████████████████████████████████████████████████████████████████████████| 1/1 [02:42<00:00, 162.10s/it]
------------------------------------------------------Test Results------------------------------------------------------
✅ Test Sync scaffold from a commit passed successfully
✅ Test Sync markdown-pages from a TiDB Cloud PR passed successfully
✅ Test Sync markdown-pages from a docs PR passed successfully
✅ Test Sync markdown-pages from a docs-cn PR passed successfully
✅ Test Sync markdown-pages from a TiDB Operator PR passed successfully
✅ Test Sync markdown-pages from multiple PRs passed successfully
Tests passed: 6 of 6 413.09s
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