docs/data/reusables/code-scanning/summary-metrics.md

Summary metrics include:

• Lines of code in the codebase (used as a baseline), before creation and extraction of the {% data variables.product.prodname_codeql %} database
• Lines of code in the {% data variables.product.prodname_codeql %} database extracted from the code, including external libraries and auto-generated files
• Lines of code in the {% data variables.product.prodname_codeql %} database excluding auto-generated files and external libraries