integrating welcome bot

[Sloth-Panda]

Hello there, I can add a welcome bot config file having a proper message that will show up when any user will open up an issue or pull-request for the first time as a part of SWOC. For reference, kindly check out: https://github.com/apps/welcome

[Sloth-Panda]

also please add swoc and leve tags to these issues

[Sloth-Panda]

@nikhilbghodke would like too make this please let me know