String.replaceMap(parameterList);

app.js

"hello world".replaceMap({
    " ":   ", ",
    "wor": "it's",
    "ld":  " me"
});

output.txt

"hello, it's me"

sample.md

Test

Copy and paste to the console:

String.prototype.replaceMap = function(parameters) {
    var string = this.toString();
    Object.keys(parameters).forEach(function(key){
        string = string.replace(new RegExp(key, 'g'), parameters[key]);
    });

    return string;
}

"hello world".replaceMap({
    " ":   ", ",
    "wor": "it's",
    "ld":  " me"
});

String.prototype.js

String.prototype.replaceMap = function(parameters) {
    var string = this.toString();
    Object.keys(parameters).forEach(function(key){
        string = string.replace(new RegExp(key, 'g'), parameters[key]);
    });

    return string;
}