[DX] Add "setup-downgrade" to init easy downgrade builds, similar to "setup-ci"

[TomasVotruba]

Rector is the only tool that can handle downgraded. Yet setting up the downgrade process is quite challenging when it comes to:

• path defintion
• scoper setup
• github action content
• /build directory logic including downgraded composer.json
• custom change in main composer.json, e.g. platform checks false etc.

Instead making this workflow available only to few who struggle through, there should be a helper command than handles this for users and make downgrading piede of cake 💪

Note: make use of questiosn and link similar to composer require of a private package in composer. Ask for the token, and place it in the code for user themselves.

[TomasVotruba]

Hi @samsonasik , could you add this command? Should be similar to setup-ci, just with different contents.

It should dump all these files:

• https://github.com/TomasVotruba/lines/tree/main/build
• https://github.com/TomasVotruba/lines/blob/main/.github/workflows/downgraded_release.yaml
• https://github.com/TomasVotruba/lines/blob/main/scoper.php
• https://github.com/TomasVotruba/lines/blob/main/prefix-code.sh

[samsonasik]

I will try