[fix] force utf-8 encoding in windows

src/main/java/org/humanistika/oxygen/tei/completer/response/impl/JSONTransformer.java

@@ -25,6 +25,7 @@
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -87,7 +88,7 @@ public void transform(final InputStream content, final Path transformation, fina
                 final char buf[] = new char[4096];
                 int read = -1;
                 try(final Reader jsonReader = new StringReader(jsonResult);
-                    final Writer writer = new OutputStreamWriter(result)) {
+                    final Writer writer = new OutputStreamWriter(result, UTF_8)) {
                     while((read = jsonReader.read(buf)) > -1) {
                         writer.write(buf, 0, read);
                     }