Adds a Term Store Administrator to the TermStore object.
Assembly: Microsoft.SharePoint.Taxonomy (in Microsoft.SharePoint.Taxonomy.dll)
Term Store Administrators have the following permissions on the TermStore and within all Group objects of the TermStore
Term Store Administrators can read and modify properties of the TermStore, they can add and remove groups, and they can add and remove group managers from groups. Additionally they can perform all operations that a contributor or group manager can perform within any Group in the TermStore. The current user must have TaxonomyRights.AddManageTermStorePermissions permission to use this method. Specifically, farm administrators have the TaxonomyRights.AddManageTermStorePermissions permission. Call the CommitAll() method to save this change to the database.