Update readme.md

Author: zylo117

readme.md

@@ -8,7 +8,7 @@ If you have troubles training a dataset, and if you are willing to share your da
 
 Requirements:
 
-1. The total number of the image of the dataset should not be larger than 10K.
+1. The total number of the image of the dataset should not be larger than 10K, and its capacity should be under 5GB.
 
 2. The dataset should be in the format of this repo.