trim down vscode settings and use ruff for format instead of black

[coretl]

• .devcontainer should be replaced by a link to the one in the root
• .vscode should be replaced by a link to the one in the root
• .pre-commit-config.yaml should be replaced by a link to the one in the root
• pyproject.yaml should have no references to black
• any reference to black in docs should say ruff instead