Add functionality adds labels specified to the list of labels:

@mxnet-label-bot add [comma separated labels]

@mxnet-label-bot add [Good First Issue, Doc]

Remove functionality removes labels specified from the list of labels:

@mxnet-label-bot remove [comma separated labels]

@mxnet-label-bot remove [bug, question]

Update functionality updates the labels of the issue to only the labels specified in the list:

**Warning** : This removes all previous labels on the repo

@mxnet-label-bot update [comma separated labels]

@mxnet-label-bot update [website, Python]