chore: update readme documentation

[Huerte]

Type

• Bug fix
• New feature
• Documentation
• Refactor / internal

Overview

added support for full github urls in the gitgo init --template command and cleaned up some formatting in the readme. users can now copy and paste full urls directly from their browser instead of manually trimming them down to the owner/repo format.

Closes #

Changes

• init.py: added a _parse_template_slug helper that extracts the owner/repo slug from full https urls and .git clone links.
• test_init.py: added unit tests to verify the new template parsing logic handles valid urls and rejects invalid ones.
• README.md: added examples for the new --template url formats and fixed a formatting issue where changelog bullets were accidentally placed inside the gitgo init reference section.
• CHANGELOG.md: documented the template url parsing feature under the unreleased section.

How to Test

1. pip install -e ".[dev]"
2. pytest tests/test_init.py -v
3. Expected result: the new test_parse_template_slug test passes successfully.
4. gitgo init my-test-app --template https://github.com/Huerte/GitGo.git
5. Expected result: it successfully extracts Huerte/GitGo, downloads the template archive, and scaffolds the local project.

Checklist

• I tested my changes locally and they work
• I updated CHANGELOG.md under the [Unreleased] section
• I updated README.md (if I added or changed a command)
• I added or updated tests for my change (if applicable)
• My change does not break any existing commands (if it does, describe the impact in the Overview)