Summary

Define consistent LF line endings across Windows, Linux and macOS.

Changes

• Add .gitattributes to normalize text files and keep LF in checkouts.
• Add .editorconfig with end_of_line = lf, which editors and Prettier can use.
• Document the rule in the Norwegian README.
• Keep this independent of the Prettier configuration introduced in PR Implement frontend GraphQL integration, tests and tooling #4.

Testing

• npm test: 6 tests passed on the current main-based branch.
• npm run lint: passed.
• npm run build: passed.
• git diff --cached --check: passed before commit.
• Verified a separate checkout with core.autocrlf=true: all tracked text files used LF.
• Verified PR Implement frontend GraphQL integration, tests and tooling #4 in a separate copy with the new configuration: its unchanged npm run format:check passed without a line-ending override, and Prettier resolved endOfLine to lf.

Closes #5