add number modifier to default configuration

[pearsonradu]

Description of the change

Update the default configuration to contain the number modifier. Currently, if you try to add the below sample the generator will fail saying number is an unknown modifier.

YAML

## @param test [string,number] A test value to represent a string or a number
test: ""

Output

Error: Unknown modifier: number for parameter test

Benefits

Allows consumers to use the number modifier without providing a custom configuration.

Possible drawbacks

Applicable issues

Additional information

Checklist

• [ x ] Version bumped in package.json and package-lock.json according to semver.
• [ x ] New features are documented in the README.md
• [ x ] New features contain a new test at the tests folder
• [ x ] All tests pass running npm test

[pearsonradu]

@fmulero can this be reviewed?