TEP-0075: Add a pipeline run example with both object param and result

The pipeline consists of two tasks
- task 1 writes the values of an object param to an object result.
- task 2 uses task1's object result as the value of its own object param,
and echo that object param.

examples/v1beta1/pipelineruns/alpha/pipeline-object-param-and-result.yaml

@@ -0,0 +1,86 @@
+apiVersion: tekton.dev/v1beta1
+kind: Task
+metadata:
+  name: write-param-to-result
+spec:
+  params:
+    - name: arg
+      type: object
+      properties:
+        url:
+          type: string
+        commit:
+          type: string
+  results:
+    - name: object-result
+      type: object
+      properties:
+        foo:
+          type: string
+        bar:
+          type: string
+  steps:
+    - name: write-result
+      image: bash:latest
+      script: |
+        #!/usr/bin/env bash
+        echo -n "{\"foo\":\"$(params.arg.url)\",\"bar\":\"$(params.arg.commit)\"}" | tee $(results.object-result.path)
+---
+apiVersion: tekton.dev/v1beta1
+kind: Task
+metadata:
+  name: echo-param
+spec:
+  params:
+    - name: arg
+      type: object
+      properties:
+        foo:
+          type: string
+        bar:
+          type: string
+  steps:
+    - name: write-result
+      image: bash:latest
+      args: [
+        "echo",
+        "--foo=$(params.arg.foo)",
+        "--bar=$(params.arg.bar)"
+      ]
+---
+apiVersion: tekton.dev/v1beta1
+kind: Pipeline
+metadata:
+  name: pipeline-test
+spec:
+  params:
+    - name: gitrepo
+      properties:
+        url: {}
+        commit: {}
+  tasks:
+    - name: task1
+      params:
+        - name: arg
+          value: $(params.gitrepo[*])
+      taskRef:
+        name: write-param-to-result
+    - name: task2
+      params:
+        - name: arg
+          value: "$(tasks.task1.results.object-result[*])"
+      taskRef:
+        name: echo-param
+---
+apiVersion: tekton.dev/v1beta1
+kind: PipelineRun
+metadata:
+  name: pipelinerun-object-param-result
+spec:
+  params:
+    - name: gitrepo
+      value:
+        url: abc.com
+        commit: sha123
+  pipelineRef:
+    name: pipeline-test