Link security advisory to README (#1694)

http/README.md

@@ -3,8 +3,10 @@
 This http package is purely for the demonstration purposes and is used by sample
 applications like https://github.com/blevesearch/bleve-explorer.
 
-Please be aware that the http handler implementations neither provide exhaustive 
-user input validations nor authentication or authorization of the user access. 
+Please be aware that the http handler implementations neither provide exhaustive
+user input validations nor authentication or authorization of the user access.
 
-So, it is recommended to remain cautious against the use of the http package in 
-production use cases.
+So, it is strongly recommended that users exercise caution while using the http
+package in production situations.
+
+[Here](https://github.com/blevesearch/bleve/security/advisories/GHSA-9w9f-6mg8-jp7w) is the security advisory on this.