add webex-bot-node-framework

[Stève Sfartz]

https://github.com/webex/webex-bot-node-framework#webex-teams-bot-framework-for-node-js

[Stève Sfartz]

Project sounds promising:

The primary reason for creating the webex-node-bot-framework was to create a framework based on the webex-jssdk which continues to be supported as new features and functionality are added to Webex.