Display nudge #_2 when users have a MR without a pipeline

Overview

Nudging users to set up a pipeline for the first time by displaying a series of in-app messages. The first of four in-app messages will articulate the benefits of using pipelines with a call to action.

Requirements

1. Show nudge #_2 after a user has seen nudge #_1
2. And the user has selected the "show me how" button

Exclusions

1. Do not show this to any user who does not have access to pipelines as a feature
2. Do not show this to any user who closed nudge #_1
3. Do not show this to any user who has clicked the "no thanks" button

/cc @dstull @jackie_fraser @pcalder