[doc] Groups can be browsable if they contain at least one public project.

doc/permissions/permissions.md

@@ -41,6 +41,11 @@ If a user is a GitLab administrator they receive all permissions.
 
 ## Group
 
+In order for a group to appear as public and be browsable, it must contain at
+least one public project.
+
+Any user can remove themselves from a group, unless they are the last Owner of the group.
+
 | Action                  | Guest | Reporter | Developer | Master | Owner |
 |-------------------------|-------|----------|-----------|--------|-------|
 | Browse group            | ✓     | ✓        | ✓         | ✓      | ✓     |
@@ -48,5 +53,3 @@ If a user is a GitLab administrator they receive all permissions.
 | Create project in group |       |          |           | ✓      | ✓     |
 | Manage group members    |       |          |           |        | ✓     |
 | Remove group            |       |          |           |        | ✓     |
-
-Any user can remove themselves from a group, unless they are the last Owner of the group.