Allow to star groups (and subgroups)
### Problem to solve
As a developer with special debugging and problem solving skills, I'm assigned to lots of different projects on our server.
While acting as a firefighter, I see tons of projects in my projects overview page. It's hard to find the projects and groups I'm personally working in.
For projects, I can star a project and mark it as favorite.
**This feature is missing for groups and subgroups.**
### Further details
Here are three use cases / reasons for this feature:
1. Projects can be stared and thus marked as favorite projects. To organize the quick access to groups and subgroups, it would be nice to allow staring (sub-)groups too.
This would also add orthogonality to GitLab.
2. Many projects are split into multiple projects. Thus, the important entry point to work in is not a single project, it's at least a subgroup.
Example structure:
* **Customer project 1** <= this would be stared
* Libs
* Library Project 1
* Library Project 2
* Library Project 3
* Main Project
* Specification
* Documentation
3. This need is strengthened by moving many GitLab core features from project to group level like:
- Epics
- Group Milestones
### Proposal
* Add a button to star a group / subgroup.
* Add a tab / view to the groups listing to show only stared (sub)groups.
* Add an entry to the user settings to select "stared groups" as dashboard default.
Further enhancement:
* Allow pinned (sub-)groups.
(The pinned project feature is currently in discussion.)
#### Images
| Projects (star button) | Projects (starred location) | Groups (button) | Groups (location) |
| ------ | ------ | ------ | ------ |
|  |  |  |  |
### What does success look like, and how can we measure that?
### Links / references
This could be interesting together with pinned projects.
issue