v1.40.0

• Add concept of a default lint or breaking rule, which is printed out as a property when running buf config ls-{breaking,lint}-rules. Default rules are those rules which are run if no lint or breaking rules are explicitly configured in your buf.yaml.
• Rename DEFAULT lint rule category to STANDARD. With the concept of default rules being introduced, having a category named DEFAULT is confusing, as while it happens that all the rules in the DEFAULT lint category are also default rules, the name has become overloaded. As with all buf changes, this change is backwards-compatible: the DEFAULT lint category continues to work, and always will. We recommend changing to STANDARD, however.