Custom --grammar support [for koboldcpp] (#1161)

* Basic kobold grammar implementation

This is probably jank as all hell, I don't write js, but I think I got it to work.

* No value by default

* Visual cleanup

+ reworded it a bit

* Conditionally enable Grammar based on version flag. Fix layout

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Co-authored-by: Cohee <18619528+Cohee1207@users.noreply.github.com>

server.js

@@ -375,6 +375,7 @@ app.post("/generate", jsonParser, async function (request, response_generate) {
             mirostat: request.body.mirostat,
             mirostat_eta: request.body.mirostat_eta,
             mirostat_tau: request.body.mirostat_tau,
+            grammar: request.body.grammar,
         };
         if (!!request.body.stop_sequence) {
             this_settings['stop_sequence'] = request.body.stop_sequence;