./home.html
./settings.html
./contact.html

./nav.js <-- common - used in all html files
./home.js <-- used only in home.html, below follow the same rule
./settings.js
./contact.js

./home.js
import $ from "jquery";
(...)

entry: {
  home: "./resources/js/sections/home.js",
  settings: "./resources/js/sections/settings.js",
  (...)
}
(...)
output: {
  filename: '[name].js',
}

import nav from ./nav.js
nav();

entry: {
  (...)
  nav: "./resources/js/sections/nav.js"
}

npm install html-loader html-webpack-plugin --save-dev