Readme.md and wiki home do not describe what add-ins do.

From Readme.md and wiki home is not obvious What add-ins do? Why it's better than call autofac or similar directly?

Also in https://github.com/jorgehmv/FodyDependencyInjection/wiki/Autofac it's not obvious, does Avoid injecting a global switch, or developer has control to apply for certain methods/classes?