[ALL] NPM packages are missing file extensions in ES6 exports

[jogibear9988]

Bug report

I want to use the packages in a ES6 environment without a bundler, but only using a importmap. This would work, but all your packages contain imports without file extensions, so this does not work.
NPM packages with ES6 export should contain file extensions in the package, or list all the named exports in the exports section.

Possible solution

Add file extensions in generated JS files, or add the .js file already in the typescript code.

For example here:

material-components-web/packages/mdc-top-app-bar/index.ts

Line 24 in c43b343

export * from './adapter';

(or everywhere else)