GitHub Actions and no major contrib updates

Features

• Updated Renovate config to update minor and patch of contribs. Major versions of contribs usually require manual resolution.
• Added GitHub Actions config

Fixes

• Fixed required.php and config.platform configs in composer.json to follow correct version numbering.
• Fixed Renovate not being pinned to a specific version. This resulted in a suddenly broke Renovate workflow if regression defects were introduced in Renovate.

Excluded Drush

Drush is too important to update automatically.

Only composer packages

1.1.0

Limited only to Composer packages.

Fully working example

1.0.0

Added schedule.