There are many ways to insert a carriage return (new line feed) in a resource string in a resx file but this is the simplest in my opinion.
Just open up the resx file in Visual Studio, edit the string content that you want carriage returns in, and just do a ‘SHIFT’ + ‘ENTER’ everywhere you need a carriage return. Yup, that simple.
For example, if you need
Just type “Hi”, followed by SHIFT + ENTER and then “There!”.