chore: add keepNames tsup option

[DTrombett]

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

Add the keepNames option to tsup configs to avoid errors or such to have a minified name like D.

Status and versioning classification:

• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating
• This PR only includes non-code changes, like changes to documentation, README, etc.

[ImRodry]

Can we please just remove minify? Looking at source code to trace back an error is extremely painful with this option and the size reduction is very small (although relatively significant, it’s only 15kb in rest for example)

[vladfrangu]

I don't see how seeing where in our code the issue started from helps you at all

[ImRodry]

I don't see how seeing where in our code the issue started from helps you at all

There can always be bugs in the package and even if there aren’t it’s good to know what methods are being called and how the code reached that point. That should not be taken away from us