add starnet doc & test=document_fix

doc/doc_en/algorithm_rec_starnet.md

@@ -80,7 +80,9 @@ STAR-Net text recognition model inference, you can execute the following command
 ```shell
 python3 tools/infer/predict_rec.py --image_dir="./doc/imgs_words_en/word_336.png" --rec_model_dir="./inference/rec_starnet/" --rec_image_shape="3, 32, 100" --rec_char_dict_path="./ppocr/utils/ic15_dict.txt"
  ````
+
 ![](../imgs_words_en/word_336.png)
+
 The inference results are as follows: