BREAKING CHANGE - the as variable operator (e.g. .a as $x) now makes a copy of the node(s) at the
path rather than a reference. This is in order to make it work more like the jq equivalent.

This means any updates made to that variable do not update the original.

There's a new operator ref that will make a reference (and allow multiple updates to the original path by referencing the variable).
Sorry for any inconvenience caused!.

• New with operator for making multiple changes to a given path
• New contains operator, works like the jq equivalent
• Subtract operator now supports subtracting elements from arrays!
• Fixed Swapping values using variables #934
• Github Action now properly supports multiline output #936, thanks @pjxiao
• Fixed missing closing bracket validation #932