feat: Improve handling of not enough keywords topics

app.py

@@ -170,6 +170,8 @@ def generate_plot(
                 except IndexError:
                     break
                 cluster_keyword[label].append(cluster_words[most_descriptive[0]])
+            if len(cluster_keyword[label]) == 1:
+                cluster_keyword[label] = cluster_keyword[label][0]
             cluster_keyword[label] = ', '.join(cluster_keyword[label])
         encoded_labels_keywords = [cluster_keyword[encoded_label] for encoded_label in encoded_labels]
         embeddings_2d = get_tsne_embeddings(embeddings)