Allow independent versioning for custom react-scripts forks

[ghost]

Is your proposal related to a problem?

Yes.

I'm currently working on a custom version of react-scripts for my company to use so that we can build new react-apps with our own webpack configs & pre-installed dependencies. However, the problem is that in createReactApp.js line 436, const templatesVersionMinimum = '3.3.0'; it makes it so that in order for CRA to actually build the src files properly I have to specify a minimum package version of 3.3.0 I get the motivation for that code. However, if I'm working on a new customized version of a package, I don't really want to start at version 3.3.0, I want to start at 0.0.1 or at least 1.0.0.

Describe the solution you'd like

I think the templatesVersionMinimum constant being set to 3.3.0 should really only be applied if you intend to use the default package of react-scripts that CRA uses. Otherwise it really shouldn't have that limit in place, because other people might not want to begin their package versioning at 3.3.0. Of course, people using custom-react scripts intending to use templates would need to be sure their customizations don't break the template support introduced in 3.3.0 so I guess the scope expands a bit further than simply setting a conditional wherein that templatesVersionMinimum isn't set at all when a non-default react-scripts is specified.

Describe alternatives you've considered

1. Setting my package version to 3.3.0
   --This works, but I mean it's pretty gross.

2. Leaving modern society and living in a cave eating berries
   --This doesn't fix the problem per se. But it does remove it from a being a problem I need to deal with. Not an ideal solution either.