Add version 2 to required node-fetch's

[TheMonDon]

Please describe the changes this PR makes and why it should be merged:
CommonJS

node-fetch from v3 is an ESM-only module - you are not able to import it with require().

If you cannot switch to ESM, please use v2 which remains compatible with CommonJS. Critical bug fixes will continue to be published for v2.

npm install node-fetch@2

Status

• Code changes have been tested against the Discord API and the discord.js wrapper, or there are no code changes
• Documentation has been added/modified, or there is nothing to change (docs/mods.json)

Semantic versioning classification:

• This PR changes DBM's interface (methods or parameters added to default methods)
• This PR only includes non-code changes, like changes to documentation, README, etc.