Re-add some of the labels I previously removed

After discussion with @vdemeester:
* Re-added area/release and area/test-infra (but renamed to
  area/plumbing) - although we have the plumbing repo to for the
  code we need for this, sometimes we'll need work done for it in
  the other repos
* The flake label - although I _want_ to treat these as an emergency
  such that we wouldn't ever need the label, that's not what's happening
  so I have to admit it's useful!
* I also re-added traige/duplicate, traige/needs-information and the
  shrug label but I'd like to discuss these further in the next
  productivity WG meeting, for the reasons in the comments I included

label_sync/labels.yaml

@@ -61,12 +61,24 @@ default:
       prowPlugin: label
       addedBy: anyone
 
-    # Kinds and areas
+    # Areas
     - color: 0052cc
       description: Indicates an issue or PR that deals with the API.
       name: area/api
       target: issues
       addedBy: label
+    - color: 7057ff
+      description: Indicates an issue on release (process, tasks).
+      name: area/release
+      target: issues
+      addedBy: label
+    - color: 10677f
+      description: Issues or PRs related to the plumbing infrastructure but needing attention in a non-plumbing repo.
+      name: area/plumbing
+      target: both
+      addedBy: label
+
+    # Kinds
     - color: e11d21
       description: Categorizes issue or PR as related to a bug.
       name: kind/bug
@@ -75,6 +87,9 @@ default:
       target: both
       prowPlugin: label
       addedBy: anyone
+    - color: f7c6c7
+      description: Categorizes issue or PR as related to a flakey test. Please escalate this and treat it as an emergency.
+      name: kind/flake
     - color: c7def8
       description: Categorizes issue or PR as related to cleaning up code, process, or technical debt.
       name: kind/cleanup
@@ -105,6 +120,30 @@ default:
       target: both
       prowPlugin: label
       addedBy: anyone
+
+    # For further discussion in the next Productivity WG meeting
+
+    # Would like to understand when this label should be used vs. using GitHub syntax or ZenHub
+    - color: d455d0
+      description: Indicates an issue is a duplicate of other open issue.
+      name: triage/duplicate
+      previously:
+        - name: duplicate
+      target: both
+    # needs-information seems like it serves the same function as kind/question or "waiting for response"
+    - color: d455d0
+      description: Indicates an issue needs more information in order to work on it.
+      name: triage/needs-information
+      target: both
+      addedBy: humans
+    # If I was contributing to a repo, went to the trouble to create an issue or PR, and a maintainer
+    # responded by shrugging, I think it would make me feel my contribution wasn't appreciated
+    - color: f9d0c4
+      description: ¯\\\_(ツ)_/¯
+      name: "¯\\_(ツ)_/¯"
+      target: both
+      prowPlugin: shrug
+      addedBy: humans
 
 
     ##########################################################################