Create a profile field or "announcement" for new job attributable to brigade

Many members end up in new jobs because of their involvement with the brigade, we should provide a way for members to share when that happens (or that it already happened). This could create a badge in someone's profile, add them to some sort of wall, and give the brigade much-needed metrics on ROI for sponsors

No files, tests, or implementation entry points are identified in the issue. First clarify whether the feature is a profile field, an announcement wall, a badge, sponsor metrics, or some combination; done should be defined by an agreed design and measurable ROI reporting behavior.

索引モデルが issue の本文から書いたものです。