Update Outbox Quarkus extension yaml

Per a discussion with Guilluame, he asked that we modify our extension description to conform to their preferred way of starting the description using a verb, e.g.:

Use outbox pattern with Debezium

Additionally the guide link should be updated to point to 1.2. While what we have is sufficient and will be included in Quarkus 1.4.0.Final when released, he asked that we do this as a follow-up.