Formats missing in esbuild bundle output

[cprass]

When bundling winston with esbuild, the format exports are missing because they are required dynamically. Esbuild currently can't handle dynamic import resolution.

evanw/esbuild#56 explains why esbuild can't handle the dynamic imports, there seems to be a plugin on the way tho (evanw/esbuild#700).

I guess those lines are the main issue: https://github.com/winstonjs/logform/blob/b91bfa5c32a6077adcf2526ee8d3414c7171e557/index.js#L24#L32

Maybe related to #5

[empperi]

There is already a PR for this open, it just needs merging #117

I'm personally waiting on this PR before I can continue with my personal project.