add url for PADDLE_ENFROCE rewriting hint (#21513)

test=develop test=document_fix

tools/check_api_approvals.sh

@@ -120,7 +120,7 @@ fi
 
 ALL_PADDLE_ENFORCE=`git diff -U0 upstream/$BRANCH |grep "+" |grep -zoE "PADDLE_ENFORCE\(.[^,\);]+.[^;]*\);\s" || true`
 if [ "${ALL_PADDLE_ENFORCE}" != "" ] && [ "${GIT_PR_ID}" != "" ]; then
-    echo_line="PADDLE_ENFORCE is not recommended. Please use PADDLE_ENFORCE_EQ/NE/GT/GE/LT/LE or PADDLE_ENFORCE_NOT_NULL or PADDLE_ENFORCE_CUDA_SUCCESS instead.\nYou must have one RD (chenwhql (Recommend) , luotao1 (Recommend) or lanxianghit) approval for the usage (either add or delete) of PADDLE_ENFORCE.\n${ALL_PADDLE_ENFORCE}\n"
+    echo_line="PADDLE_ENFORCE is not recommended. Please use PADDLE_ENFORCE_EQ/NE/GT/GE/LT/LE or PADDLE_ENFORCE_NOT_NULL or PADDLE_ENFORCE_CUDA_SUCCESS instead, see [ https://github.com/PaddlePaddle/Paddle/wiki/PADDLE_ENFORCE-Rewriting-Specification ] for details.\nYou must have one RD (chenwhql (Recommend) , luotao1 (Recommend) or lanxianghit) approval for the usage (either add or delete) of PADDLE_ENFORCE.\n${ALL_PADDLE_ENFORCE}\n"
     check_approval 1 6836917 47554610 22561442
 fi