[V3] Migration should be done with a codemod?

Is your feature request related to a problem? Please describe. I found after writing the documentation there are several steps to migrate a large application:

• NumberFormat and DateFormat components were removed. Use date and number formats from @lingui/core package instead.
• Change import of components to macro from react package
• plural parameters changed:

- plural({ value, one: "# book", other: "# books" })
+ plural(value, { one: "# book", other: "# books" })

• i18n.t(), i18n.plural(), i18n.select() and i18n.selectOrdinal() methods are removed and replaced with macros.
• Rename I18nProvider.defaultRender prop to I18nProvider.defaultComponent
• Macros don’t need to be wrapped inside i18n._: i18n._(t'Message') => t'Message'

To not implement:

• setupI18n can be safely removed and i18n can be imported from @lingui/core (if setupI18n has some parameters, I would leave it for user to handle it), this is a easily migration for the end user so probably it’s not the worth time to implement a codemod to this

Describe proposed solution I propose to write a codemod for do all this migration with a just

npx codemod lingui-v2-to-v3

the user only should migrate his i18n setup from a declarative API to the new i18n.load, and i18n.activate

What do you think @tricoder42? Probably I could get it working tomorrow or the next, with this and the documentation finished we’ll have a good adoption.

[tricoder42]

@semoal I’ve invited you as a collaborator. Let me know if it enables write access for you

[semoal]

I've already got 2/7 (in 1 hour or less), it's my first time with codemods and AST, i'll try to give it some time tomorrow!