Adding support for Vite

[ryanrapini]

Hey there! I don't think this package is in active development anymore. A project I have relies on this package and I wanted to continue to use it. Unfortunately when I upgraded to vite as the buildsystem, I would see the following error when trying to import this package:

[vite] Internal server error: Failed to resolve entry for package "vue-nestable". The package may have incorrect main/module/exports specified in its package.json.
  Plugin: vite:import-analysis
  File: resources/js/offers.js
      at packageEntryFailure (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:46575:15)
      at resolvePackageEntry (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:46572:3)
      at tryNodeResolve (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:46388:16)
      at ResolveIdContext.resolveId (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:46138:19)
      at async PluginContainer.resolveId (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:48952:22)
      at async TransformPluginContext.resolve (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:49113:15)
      at async normalizeUrl (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:63977:26)
      at async file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:64116:39
      at async Promise.all (index 9)
      at async TransformPluginContext.transform (file://node_modules/vite/dist/node/chunks/dep-CDnG8rE7.js:64043:7)

I went ahead and forked the repo and I'm consuming my "fixed" version in my project, so if you don't have time to test and merge these changes I understand.

** WARNING ** I don't know if my changes will break anything for anyone not using vite. I only tested this on vite. I'm not experienced with npm packaging so I may have done something horribly, horribly wrong. But it works great for me and I wanted to share in case this helps others.

Thanks for the package!