Alewis/custom webpack config for sites

[ashleymichal]

fixes #602
please advise on verbiage. it felt easier to explain context than entry, but i could be convinced otherwise.

[juanmrad]

A suggestion to give a broader example on this. and it is a suggestion, but wanted to put it here since is something I found out as I was testing:

you can have now the following folder structure:

common_modules
- common_module1
- common_module2
paths
- path1
- - index.js
- path2
- - index.js
webpack.path1.js
webpack.path2.js
wrangler.toml

This allowed us to have on the files:
webpack.path1.js:

module.exports = {
  target: 'webworker',
  entry: './paths/path1/index.js',
  mode: 'production'
};

and the index.js can easily import from the ../../modules/common_module1.js file.

This is great for monolith repos for multiple workers and paths.