Provide context to push notifications

[IAmTomahawkx]

Currently, highlight sends an embed with the message content when highlighted. This is sub-optimal as it provides little context as to the channel or user that the highlight is from.
This can be solved by providing message content alongside the embed, as discord prioritizes message content before embed content in its push notifications. Providing a message such as "IAmTomahawkx#1000 has highlighted you in channel #general-1 with keyword 'tom' " would be vastly superior to the current solution. It should be noted that user/channel mentions shouldn't be used here as those aren't rendered in notifications.