Groups
Groups allow you to put together operators from rules and call them at once, preventing duplicated code.
Groups are stored in group.rs file and nowhere else. Attempting to create a group outside of this file will result in an error.
Open rules/groups.rs and make a new group using "group" operator. Give it a unique name since we will be referencing to it later.
Example of a group called "beginner":
You can use groups in your other .rs files by the group <name> operator. Example:
