JsonPath example(s) missing in README.md

[koppor]

I crafted following code to get a String from a JSON component.

            JsonNode json = JsonNode.of(response);
            JsonNode disclaimerJson = json.getOrNull("citingPaperInfo.openAccessPdf.disclaimer");
            if (disclaimerJson != null) {
                JsonMixed disclaimerNode = JsonMixed.of(disclaimerJson);
                if (disclaimerNode.isString()) {
                    String disclaimer = disclaimerNode.string();

It seems very complex. I wonder if there is an easier method.

I would have json.getOrNull("citingPaperInfo.openAccessPdf.disclaimer").string(), but that will be an NPE 😅. Optionals would be great

json.getOptional("citingPaperInfo.openAccessPdf.disclaimer").map(::string) (or similar)

(Full code changes: JabRef/jabref#13549)