Fix contributing headers examples

Fixed

• fix: Use the copyright's holder name in the contributing template licensing examples
• docs: Add missing CHANGELOG.md file to the documentation
• fix: Fix renovate user id in the CLA allowlist

Generate CHANGELOG.md file

Added

• feat: Generate CHANGELOG.md file
• feat: Allow renovate and dependabot to skip CLA by default
• docs: Add step in the template process about signing the CLA
• docs: Add note about installing the dependencies in the "open-source-checks" workflow

Changed

• feat: Change "opensource" word to "open source" everywhere

Fixed

• chore: Replace {{repo_url}} with the actual repository URL in the repository GitHub templates

First beta version

Added

• feat: First beta version