owners: introduce aliases

The intention is to use these aliases in all repos by making
OWNERS_ALIASES a symlink to KUBERNETES_CSI_OWNERS_ALIASES.  Then
adding or removing reviewers for all repos can be done by updating
csi-release-tools and then updating repos using the normal
semi-automatic process.

While at it, several new reviewers get added to spread the load among
more people and Saad gets removed from the list of active reviewers
because he is too busy.

KUBERNETES_CSI_OWNERS_ALIASES

@@ -0,0 +1,44 @@
+# See the OWNERS docs: https://git.k8s.io/community/contributors/guide/owners.md
+
+aliases:
+
+  # SIG-Storage chairs and leads should always have approval rights in all repos.
+  # Others may be added as needed here or in each repo.
+  kubernetes-csi-approvers:
+  - jsafrane
+  - msau42
+  - saad-ali
+  - xing-yang
+
+  # Reviewers are automatically assigned to new PRs. The following
+  # reviewers will be active in all repos. Other reviewers can be
+  # added in each repo.
+  #
+  # Reviewers are encouraged to set the "Busy" flag in their GitHub status
+  # when they are temporarily unable to review PRs.
+  kubernetes-csi-reviewers:
+  - andyzhangx
+  - chrishenzie
+  - ggriffiths
+  - gnufied
+  - j-griffith
+  - Jiawei0227
+  - jingxu97
+  - jsafrane
+  - pohly
+  - xing-yang
+
+# This documents who previously contributed to Kubernetes-CSI
+# as approver.
+emeritus_approver:
+- lpabon
+- sbezverk
+- vladimirvivien
+
+# This documents who previously contributed to Kubernetes-CSI
+# as reviewer.
+emeritus_reviewer:
+- lpabon
+- saad-ali
+- sbezverk
+- vladimirvivien

OWNERS

@@ -1,11 +1,8 @@
 # See the OWNERS docs: https://git.k8s.io/community/contributors/guide/owners.md
 
 approvers:
-- saad-ali
-- msau42
+- kubernetes-csi-approvers
 - pohly
 
 reviewers:
-- saad-ali
-- msau42
-- pohly
+- kubernetes-csi-reviewers

OWNERS_ALIASES

@@ -0,0 +1 @@
+KUBERNETES_CSI_OWNERS_ALIASES