docs: add examples of configuration

examples/main_test.go

@@ -28,6 +28,14 @@ func TestBuildflow(t *testing.T) {
 			title: "task.when is true",
 			file:  "task_when_true.yaml",
 		},
+		{
+			title: "read_file",
+			file:  "read_file.yaml",
+		},
+		{
+			title: "command's standard input",
+			file:  "stdin.yaml",
+		},
 		{
 			title: "buildflow run fails as expected",
 			file:  "fail.yaml",

examples/read_file.yaml

@@ -0,0 +1,17 @@
+---
+phases:
+- name: main
+  tasks:
+  - name: foo
+    read_file:
+      path: read_file.yaml
+  - name: bar
+    command:
+      command: |
+        echo "$FOO"
+      env:
+      - key: FOO
+        value: |
+          {{with GetTaskByName .Tasks "foo"}}{{.File.Text}}{{end}}
+    dependency:
+    - foo

examples/stdin.yaml

@@ -0,0 +1,10 @@
+---
+phases:
+- name: main
+  tasks:
+  - name: hello
+    command:
+      stdin: |
+        foo
+        bar
+      command: grep bar