Make changelog optional

[sverhoeven]

Fixes #462

Description

• [x] I have read the contribution guidelines
• [x] This update is in line with what is recommended in the Python chapter of the Guide
• [x] All user facing changes have been added to CHANGELOG.md

Instructions to review the pull request

Create a python-template-test repo on GitHub (will be overwritten if existing)

# Create a temporary directory by running the following command. Keep the XXXXXX in the directory name. 
cd $(mktemp -d --tmpdir py-tmpl-XXXXXX)
# Use --vcs-ref <pr-branch> to point to the branch you want to test
copier copy --vcs-ref <pr-branch> https://github.com/<pr-user>/python-template .
# Fill with python-template-test info
# Create a local git repo to push to GitHub to trigger CI actions
git init
git add --all
git commit -m "First commit"
git remote add origin git@github.com:<you>/python-template-test.git
git push -u origin main -f
# Create a local environment to test your generated package locally
python -m venv env
source env/bin/activate
python -m pip install --upgrade pip setuptools
python -m pip install '.[dev,publishing]'

Yes changelog

🎤 Add a change log to keep track of changes in the package
   Yes

Should create CHANGELOG.md and mention it in other files.

No changelog

🎤 Add a change log to keep track of changes in the package
   No

Should not create CHANGELOG.md or any mention of it in other files.