Split in several modules

[nlepage]

• Put the lodash functions in a different module in the form of a plugin (in a different repository) Add lerna and split project #138
• Have an immutadot core with no peer dependency on lodash 🚧 Remove lodash from immutadot package #143
• Add more plain JS functions to immutadot core (Array.push, Object.assign, etc.) Add core functions #165
• Update documentation to reflect the new organization -> Update documentation to reflect the new organization #183

[frinyvonnick]

Maybe we should use lerna to keep a monorepo and take benefits of the multiple packages architecture.

[nlepage]

OK lerna seems to be good fit for the project, multirepo wouldn't bring any benefits in comparison.