新增learn-kubernetes（https://github.com/yyong-brs/learn-kubernetes）相关文件

learn/learn-kubernetes-master/kiamol/ch20/lab/solution/timecheck-crd.yaml

@@ -0,0 +1,39 @@
+apiVersion: apiextensions.k8s.io/v1  # minimum 1.16
+kind: CustomResourceDefinition
+metadata:
+  name: timechecks.ch20.kiamol.net
+  labels:
+    kiamol: ch20
+spec:
+  group: ch20.kiamol.net
+  scope: Namespaced
+  names:
+    plural: timechecks
+    singular: timecheck
+    kind: TimeCheck
+    shortNames:
+    - tc
+  versions:
+    - name: v1
+      served: true
+      storage: true
+      schema:
+        openAPIV3Schema:
+          type: object
+          properties:
+            spec:
+              type: object
+              properties:
+                environment:
+                  type: string
+                interval:
+                  type: integer 
+      additionalPrinterColumns:
+        - name: Environment
+          type: string
+          description: Environment
+          jsonPath: .spec.environment
+        - name: Interval
+          type: string
+          description: Interval
+          jsonPath: .spec.interval