add other webshell collect repository
url : https://github.com/tdifg/WebShell
add public-shell repository
url : https://github.com/BDLeet/public-shell
add web-backdoors
url : https://github.com/all3g/fuzzdb/tree/master/web-backdoors
add web-shell
url : [https://github.com/BlackArch/webshells](https://github.com/BlackArch/webshells
add webshellSample
url : https://github.com/tanjiti/webshellSample
add Ridter'Pentest backdoor tools
url : https://github.com/Ridter/Pentest/tree/master/backdoor
add xl7dev'WebShell
url : https://github.com/xl7dev/WebShell 小乐天 From: Knownsec