Parenthesis (round brackets) in a variable name prevents the usage of that variable

[JunaidZA]

Describe the bug
Parenthesis (round brackets) in a variable name prevents the usage of that variable, and a single parenthesis, either one, breaks the Cottle evaluation and throws an error on the button.

To Reproduce
Steps to reproduce the behavior:

1. Open Macro Deck on PC
2. Create a variable with a parenthesis (brackets) in its name eg: 'test(1)' or 'test)2'
3. Try to use that variable on a button
4. Note the value does not appear
5. If you try a single parenthesis, you get an error when trying to use the variable: "Error: expected block continue or block end, found 3"

Expected behavior
The variable is able to be used.

Additional context
I have not tested this bug on the stable version, only on the latest beta (b12).
Cottle.Document.CreateDefault method incorrectly creates the DocumentResult when a template with parenthesis is passed in.

Possible solution
Macro Deck could strip out or replace any parenthesis in variable names like it does with slashes, periods, spaces and pipes.