Merge branch 'bw-update-issue-board-doc' into 'master'

Clarify last board navigation documentation

Closes gitlab-ee#7760

See merge request gitlab-org/gitlab-ce!22618

doc/user/project/issue_board.md

@@ -176,8 +176,8 @@ Clicking on the current board name in the upper left corner will reveal a
 menu from where you can create another Issue Board and rename or delete the
 existing one.
 
-Clicking on the main issue board link will take you to the last board
-you visited.
+When you're revisiting an issue board in a project or group with multiple boards, 
+GitLab will automatically load the last board you visited.
 
 NOTE: **Note:**
 The Multiple Issue Boards feature is available for