Add drag and drop handling to file plugin

[apecell]

I changed the names of trigger and target so this plugin is used in multiple ways.

I try to build by npm run production but failed with below errors.

ERROR in chunk notification [entry]
plugin.min.js
Conflict: Multiple assets emit to the same filename plugin.min.js

ERROR in chunk navbar [entry]
plugin.min.js
Conflict: Multiple assets emit to the same filename plugin.min.js
...

This problem is this.
https://stackoverflow.com/questions/42148632/conflict-multiple-assets-emit-to-the-same-filename

I deleted --output ./dist/plugin.min.js from the command below and succeeded.

package.json
"production": "webpack --config webpack.config.js --mode production --output ./dist/plugin.min.js",

but dist files are all minified so I send only core file plugin.

Thanks

[VizuaaLOG]

Apologies for the delay in merging this. Thank you! I appreciate it.