fix dependabot config
fix dependabot config

Right now when a PR is merged it updates the package-lock.json but not the package.json. Ideally it should do both.
We can adjust (fix) that by adding the line 'versioning-strategy: increase' to the dependabot.yml config.
That's what Bootstrap has (https://github.com/twbs/bootstrap/blob/main/.github/dependabot.yml).
Details:
https://docs.github.com/en/github/administering-a-repository/configuration-options-for-dependency-updates#versioning-strategy
h5bp/html5-boilerplate,rprouse/html5-boilerplate,rprouse/html5-boilerplate,h5bp/html5-boilerplate