Add guided walkthrough From the MR widget to the pipeline editor

Background

Pipeline suggestion was recently introduced from the MR widget to the single file editor. Pipeline suggestion helps new users to build their first pipeline, with tips and call-out boxed in the product.

Proposal

The pipeline editor is our one-stop-shop for interacting with CI/CD pipelines, we want to make sure it is the default editor users are going into when working with pipeline therefore we should add the pipeline suggestion feature to the pipeline editor

Additional details

The pipeline editor has a growing list of feature that aim for help our users create their fist pipeline, still the growing number of feature could be overwhelming for new users, pipeline suggestion could help guide our users as they do their first steps in GitLab CI/CD

I suggest to run A/B testing to determine if the guided walkthrough improve the number of new users that get to a first green pipeline.

What to measure

• Number of users that gets to their first - New users trying out GitLab CI
• Number of users that gets to their second green pipeline - since we provide an OOTB template I believe we should measure how many users get's to their second green pipeline which is probably a pipeline that they've updated

How to implement

We should have a controlled group that get's redirected to our pipeline editor as is and experimental group where we implement the guided tour, we can discuss the design in this issue.

DRI

Growth team has the skill set to drive this experiment, if needed we can collaborate with some of our FE engineers (although i suspect we wont have the capacity for this anytime soon), I am ok pushing this to 14.2 or .3 if Growth team could implement this for Pipeline authoring.