Add module field to package.json

[benmccann]

What pain point are you perceiving?.
marked does not play nicely with unbundled development tools like Snowpack, Vite, and WMR. E.g. FredKSchott/analyze-npm#9. These tools highly prefer working with ESM code, but won't discover that an ESM version is available without the module field in package.json

Describe the solution you'd like
Align the ESM and CJS versions to have the same shape (#1571 (comment)) and then add a module field to package.json

[benmccann]

Actually, there is a named export called parse, so even without changing the shape, I can get this to work in SvelteKit simply by by adding the module field. However, without the module field, I need a workaround:

			optimizeDeps: {
				include: ['marked']
			},

[UziTech]

If you want to create a PR we will be releasing v3 soon so any breaking changes can go into that release.