doc: fix readme

Author: EETagent

README.md

@@ -98,6 +98,10 @@ git clone --recursive --depth=1 https://github.com/EETagent/waifu2x-ncnn-vulkan-
 # change directory
 cd waifu2x-ncnn-vulkan-macos
 
+# rename models
+mv Waifu2X/backend/realsr-ncnn-vulkan/models Waifu2X/backend/realsr-ncnn-vulkan/models_realsr
+mv Waifu2X/backend/waifu2x-ncnn-vulkan/models Waifu2X/backend/waifu2x-ncnn-vulkan/models_waifu2x
+
 # git lfs
 git lfs install
 git lfs pull