[Doc][QA Domain & Customize Plugin] Add documentation for QA domain and CSV import feature

[narrowizard]

📚 Documentation Scope

This documentation update covers:

• The addition of the QA domain in DevLake's domain layer, including new entities such as QaProject, QaTestCase, QaApi, and QaTestCaseExecution.
• The new CSV import functionality for the QA domain via the Customize plugin, with endpoints under /plugins/customize/csvfiles/{csvfilename}.csv.

Relevant sections: Domain Layer documentation, Customize Plugin documentation, CSV Import Examples.

✏️ Describe the Change

We need to add:

1. QA Domain Layer Documentation

   • Describe the purpose of the QA domain (test management and metrics).
   • Define the core entities (QaProject, QaTestCase, QaApi, QaTestCaseExecution) with field explanations.
   • Explain the relationships between entities (e.g., a test case belongs to a project, may link to an API).

2. Customize Plugin CSV Import Documentation

   • Introduce new CSV endpoints:
     • POST /plugins/customize/csvfiles/qa_test_cases.csv
     • POST /plugins/customize/csvfiles/qa_test_case_executions.csv
     • POST /plugins/customize/csvfiles/qa_apis.csv
   • Provide example CSV file formats and sample data.
   • Explain how projects (QaProject) are created automatically during qa_test_cases import based on qa_project_id and qa_project_name.

3. Examples Section

   • Show examples of uploading CSV files to the Customize plugin.
   • Show an example mapping between MeterSphere raw data and the domain layer after import.

🖼️ Screenshots

N/A (new documentation pages and example CSV files will be added).

➕ Additional context

This update supports the new feature request to extend DevLake's capabilities for QA/test management data analysis by ingesting external CSV data. It follows the standard for domain design abstraction and CSV ingestion already used by existing domain layers like issues and CICD.

apache/devlake#8393