[CP]Fix sar infer shape (#7199)

* update doc for quickstart

* update some note

* fix sar infer shape

tools/infer/predict_rec.py

@@ -266,7 +266,7 @@ class TextRecognizer(object):
         for beg_img_no in range(0, img_num, batch_num):
             end_img_no = min(img_num, beg_img_no + batch_num)
             norm_img_batch = []
-            imgC, imgH, imgW = self.rec_image_shape
+            imgC, imgH, imgW = self.rec_image_shape[:3]
             max_wh_ratio = imgW / imgH
             # max_wh_ratio = 0
             for ino in range(beg_img_no, end_img_no):