docs: fixing wrong matrix syntax in some places

Signed-off-by: Vincent Demeester <vdemeest@redhat.com>

docs/matrix.md

@@ -175,11 +175,12 @@ tasks:
   taskRef:
     name: task-4
   matrix:
-  - name: values
-    value: 
-    - (tasks.task-1.results.foo) # string
-    - (tasks.task-2.results.bar) # string
-    - (tasks.task-3.results.rad) # string
+    params:
+    - name: values
+      value:
+      - (tasks.task-1.results.foo) # string
+      - (tasks.task-2.results.bar) # string
+      - (tasks.task-3.results.rad) # string
 ```
 
 For further information, see the example in [`PipelineRun` with `Matrix` and `Results`][pr-with-matrix-and-results].
@@ -194,8 +195,9 @@ tasks:
   taskRef:
     name: task-5
   matrix:
-  - name: values
-    value: (tasks.task-4.results.foo) # array
+    params:
+    - name: values
+      value: (tasks.task-4.results.foo) # array
 ```
 
 #### Results from fanned out PipelineTasks
@@ -574,4 +576,4 @@ spec:
 [cel]: https://github.com/tektoncd/experimental/tree/1609827ea81d05c8d00f8933c5c9d6150cd36989/cel
 [pr-with-matrix]: ../examples/v1beta1/pipelineruns/alpha/pipelinerun-with-matrix.yaml
 [pr-with-matrix-and-results]: ../examples/v1beta1/pipelineruns/alpha/pipelinerun-with-matrix-and-results.yaml
-[retries]: pipelines.md#using-the-retries-field
+[retries]: pipelines.md#using-the-retries-field

docs/pipelines.md

@@ -375,6 +375,7 @@ spec:
       taskRef:
         name: browser-test
       matrix:
+        params:
         - name: browser
           value:
           - chrome
@@ -1238,6 +1239,7 @@ spec:
         - name: url
           value: "someURL"
       matrix:
+        params:
         - name: slack-channel
           value:
           - "foo"
@@ -1696,6 +1698,7 @@ spec:
         - name: foo
           value: bah
       matrix:
+        params:
         - name: bar
           value:
             - qux