allow json (#1137)

Allow creating .json files.
Also added the json language server so syntax highlighting and validation works with the ingame editor

src/ScriptEditor/ui/OpenScript.ts

@@ -1,6 +1,7 @@
 import type { ContentFilePath } from "../../Paths/ContentFile";
 import { editor, Position } from "monaco-editor";
 import { makeModel } from "./utils";
+import { hasTextExtension } from "../../Paths/TextFilePath";
 
 type ITextModel = editor.ITextModel;
 
@@ -21,7 +22,7 @@ export class OpenScript {
     this.hostname = hostname;
     this.lastPosition = lastPosition;
     this.model = model;
-    this.isTxt = path.endsWith(".txt");
+    this.isTxt = hasTextExtension(path);
   }
 
   regenerateModel(): void {

src/ScriptEditor/ui/utils.ts

@@ -26,7 +26,7 @@ function makeModel(hostname: string, filename: string, code: string) {
     scheme: "file",
     path: `${hostname}/${filename}`,
   });
-  const language = filename.endsWith(".txt") ? "plaintext" : "javascript";
+  const language = filename.endsWith(".txt") ? "plaintext" : filename.endsWith(".json") ? "json" : "javascript";
   //if somehow a model already exist return it
   return editor.getModel(uri) ?? editor.createModel(code, language, uri);
 }