feat: add reconnectivity module; refactor: add presenceUpdaterHandler…

[StelluR]

… module

Problem:
In its current state, the role bot will throw a timeout error if the
host server loses internet for an extended period of time. It may also go into
a freezed-state where no further discord API calls take place even after the internet
has returned.

Using a process manager to automatically restart the bot in an errored-state does not
help solve this issue, since there is no way to handle connection errors upon
attempting to log into the bot itself.

Further, the code in bot.js is quite disorganized and not easy to follow.

Solution:
Check internet connection upon bot startup and only attempt to login if
the ipv4 connection is OK. Otherwise, continue attempting to connect
in 30-second intervals for when the ipv4 connection returns. These features
have been incorporated into the new reconnect.js file.

Further, update README.md to incorporate instructions for optionally using the
pm2 process manager to automatically restart the bot when in an errored state or during
times of unexpected host server reboot. This helps prevent unnecessary manual intervention.

Further, separate out the presence updating code into its own separate presenceUpdateHandler file
for the sake of readability.

[shayaantx]

no idea what im approving, but go ahead