Create a 2.0.x development branch

Problem/Motivation

When I reviewed #3326538: 2.0.2 missing core_version_requirement in Services example even though it should support Drupal 9.x, I discovered that this project has a development branch named "8.x-1.x", and tagged releases on that branch named "1.0.0", "2.0.0", "2.0.1" and "2.0.2" (semantic versioning).

That's not things are supposed to be, and IMHO creates some confusion when interacting with the repo.

Steps to reproduce

Clone the repo and examine all branches using the following command:

git branch -a

Proposed resolution

Create a development branch named "2.0.x", and use that for pushing new code being developed for that branch. The next tagged release for this branch should be named "2.0.3".

Remaining tasks

Sort this out.