docs: add html-bundler-webpack-plugin to Integrations

[webdiscus]

Hello,

I have added the html-bundler-webpack-plugin on the integrations page.

This plugin uses various templating engines, including Handlebars. The plugin allows to define Handlebars template files as entry points and use references to script and style source files directly in the template.

Thanks!

[papasmile]

lgtm

[jaylinski]

Thanks for the translation @ilharp!