Reflect latest patch release changes

We now add the information about the regression introduced in the latest
patches. The final 1.18 release is now part of the documentation, too.
Beside that, we keep the cherry-pick deadline column and add a new one
"NOTE" to add required information.

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>

data/releases/schedule.yaml

@@ -8,6 +8,7 @@ schedules:
     - release: 1.21.1
       cherryPickDeadline: 2021-05-07
       targetDate: 2021-05-12
+      note: Regression https://groups.google.com/g/kubernetes-dev/c/KuF8s2zueFs
 - release: 1.20
   next: 1.20.8
   cherryPickDeadline: 2021-06-12
@@ -17,6 +18,7 @@ schedules:
     - release: 1.20.7
       cherryPickDeadline: 2021-05-07
       targetDate: 2021-05-12
+      note: Regression https://groups.google.com/g/kubernetes-dev/c/KuF8s2zueFs
     - release: 1.20.6
       cherryPickDeadline: 2021-04-09
       targetDate: 2021-04-14
@@ -27,14 +29,16 @@ schedules:
       cherryPickDeadline: 2021-02-12
       targetDate: 2021-02-18
     - release: 1.20.3
-      cherryPickDeadline: "Conformance Tests Issue https://groups.google.com/g/kubernetes-dev/c/oUpY9vWgzJo"
+      cherryPickDeadline: 2021-02-12
       targetDate: 2021-02-17
+      note: "Conformance Tests Issue https://groups.google.com/g/kubernetes-dev/c/oUpY9vWgzJo"
     - release: 1.20.2
       cherryPickDeadline: 2021-01-08
       targetDate: 2021-01-13
     - release: 1.20.1
-      cherryPickDeadline: "Tagging Issue https://groups.google.com/g/kubernetes-dev/c/dNH2yknlCBA"
+      cherryPickDeadline: 2020-12-11
       targetDate: 2020-12-18
+      note: "Tagging Issue https://groups.google.com/g/kubernetes-dev/c/dNH2yknlCBA"
 - release: 1.19
   next: 1.19.12
   cherryPickDeadline: 2021-06-12
@@ -44,6 +48,7 @@ schedules:
     - release: 1.19.11
       cherryPickDeadline: 2021-05-07
       targetDate: 2021-05-12
+      note: Regression https://groups.google.com/g/kubernetes-dev/c/KuF8s2zueFs
     - release: 1.19.10
       cherryPickDeadline: 2021-04-09
       targetDate: 2021-04-14
@@ -57,8 +62,9 @@ schedules:
       cherryPickDeadline: 2021-01-08
       targetDate: 2021-01-13
     - release: 1.19.6
-      cherryPickDeadline: "Tagging Issue https://groups.google.com/g/kubernetes-dev/c/dNH2yknlCBA"
+      cherryPickDeadline: 2020-12-11
       targetDate: 2020-12-18
+      note: "Tagging Issue https://groups.google.com/g/kubernetes-dev/c/dNH2yknlCBA"
     - release: 1.19.5
       cherryPickDeadline: 2020-12-04
       targetDate: 2020-12-09