Update README.md

Author: Jimmy2099

stock_code/README.md

@@ -4,3 +4,5 @@
 szse: https://www.szse.cn/market/product/stock/list/index.html
 
 sse:  https://www.sse.com.cn/assortment/stock/list/share/
+
+hkse: https://www.hkex.com.hk/eng/services/trading/securities/securitieslists/ListOfSecurities.xlsx