Product Feed Rules

Specifies the parameters which are going to be used as the input of the rule.

Each rule expects params object to be of particular form:
mapping_rule: {"map_from": string}
value_mapping_rule: {string: string}
letter_case_rule: {"type": one of
regex_replace_rule: {regex: string} //regex ==a valid regular expression eg: [Cc]olou?r"to_upper", "to_lower", "capitalize_all", "capitalize_first"}
fallback_rule: {"user_default_value": string}