build: Automate release creation

[istarkov]

Description

See script title comment why it's for

• - Fix doc in SaaS
  New docs

Run ./release.sh

If release contains a migration: git commit -m "::migrate::" --allow-empty

Push created branch into the main repo, create draft Pull Request. (Draft pull request to ensure that it will not be merged by mistake)

Steps for reproduction

1. click button
2. expect xyz

Code Review

• hi @kof, I need you to do
  • conceptual review (architecture, feature-correctness)
  • detailed review (read every line)
  • test it on preview

Before requesting a review

• made a self-review
• added inline comments where things may be not obvious (the "why", not "what")

Before merging

• tested locally and on preview environment (preview dev login: 0000)
• updated test cases document
• added tests
• if any new env variables are added, added them to .env file