Update migration about parser rules

[elisherer]

Needs to add to the deprecation and migration docs that requireEnsure: false is no longer accepted.

webpack.config.js

    rules: [
      { parser: { requireEnsure: false } },

yields the error:

ValidationError: Invalid parser object. Json Modules Plugin has been initialized using a parser object that does not match the API schema.
 - parser has an unknown property 'requireEnsure'. These properties are valid:
   object { parse? }

[jamesgeorge007]

This config applies to all modules types. JS and e. g. JSON modules types. parser.requireEnsure is only valid for JS modules, while JSON module do not accept this option. They probably have to add a test: /\.[cm]?js$/ to make it only apply to JS module types.

[dasler-fw]

This config applies to all modules types. JS and e. g. JSON modules types. parser.requireEnsure is only valid for JS modules, while JSON module do not accept this option. They probably have to add a test: /\.[cm]?js$/ to make it only apply to JS module types.

Could you please explain in more details?