private boolean writeNewLine() throws IOException {
        if (indentString == null) {
            return false;
        }
        writer.write(System.lineSeparator());
        for (int i = 0; i < indent; i++) {
            writer.write(indentString);
        }
        return true;
    }
Enables human readable JSON output by inserting whitespace between values.after commas and
colons.

Based on https://github.com/ralfstx/minimal-json/blob/master/com.eclipsesource.json/src/main/java/com/eclipsesource/json/PrettyPrint.java#L84
smithy-model/src/main/java/software/amazon/smithy/model/node/internal/PrettyPrintWriter.java