Add test output tutorial (#639)

* add test output tutorial

* update test-output

* update tutorial as Max's suggestions

* update tutorial

* check char<80 & spelling

* update tutorial with ref link

---------

Co-authored-by: Pierre Equoy <pierre.equoy@canonical.com>

docs/tutorial/index.rst

@@ -27,6 +27,7 @@ journey through the product.
    :maxdepth: 1
 
    using-checkbox/basic-launcher
+   using-checkbox/test-output
 
 Extended tutorial
 -----------------

docs/tutorial/using-checkbox/test-output.rst

@@ -0,0 +1,121 @@
+.. _test_output:
+
+============================
+Test output
+============================
+
+When Checkbox runs the tests, it generates a series of outputs, which include 
+the ``ID`` and ``Category`` of the tests, along with the results of each of 
+them (if a test ID fails, the cause for the failure would be displayed). 
+
+Now we will introduce each section of the test output by performing a test 
+for audio device detection in practice.
+
+.. code-block:: none
+
+    =========[ Running job 1 / 3. Estimated time left (at least): 0:00:01 ]=========
+
+**Progress Indicator** shows the current status of the ongoing 
+job, including the total number of jobs and the number completed. It also 
+provides an estimated time left for completion, helping users track progress 
+and estimate when the test will finish.
+
+
+.. code-block:: none
+
+    -----------------------------[ Hardware Manifest ]------------------------------
+
+**Summary** provides a brief sentence to help users understand the purpose of 
+this job. 
+
+In this case, it's `Hardware Manifest
+<https://checkbox.readthedocs.io/en/latest/reference/launcher.html
+#manifest-section>`_, which provides information 
+about various hardware devices used in the tests. When certain tests involve 
+specific hardware devices, Checkbox will prompt users to inform in advance 
+whether the machine includes specific hardware devices required for testing 
+purposes.
+
+
+.. code-block:: none
+
+    ID: com.canonical.plainbox::manifest
+    Category: com.canonical.plainbox::uncategorised
+
+**ID** indicates the job IDs run during the test. and it's organized into 
+different **Categories** based on their functionalities or characteristics.
+
+
+.. code-block:: none
+
+    ... 8< -------------------------------------------------------------------------
+    ns: com.canonical.certification
+    name: checkbox-provider-base
+    has_audio_playback: False
+    has_audio_capture: True
+    
+    ------------------------------------------------------------------------- >8 ---
+
+This is the job stdout from ``com.canonical.plainbox::manifest``. If a job 
+fails or is skipped, the message will also be shown in this section.
+
+In our case, we are testing audio device detection, and the manifest was 
+prompted earlier to ask for user-provided information, this section displays 
+the collected information from the user.
+
+
+.. code-block:: none
+
+    Outcome: job passed
+
+At the end of each test, the **Outcome** will be displayed to indicate whether 
+the test has passed.
+
+
+.. code-block:: none
+
+    ------------[ Check that at least one audio playback device exits ]-------------
+    ID: com.canonical.certification::audio/detect-playback-devices
+    Category: com.canonical.plainbox::audio
+    Job cannot be started because:
+     - resource expression "manifest.has_audio_playback == 'True'" evaluates to false
+    Outcome: job cannot be started
+
+Oops! Apparently this job was skipped.Based on the stdout, it seems that this 
+issue occurred because when Checkbox asking hardware manifest, we mistakenly 
+set ``has_audio_playback`` to ``False``. Consequently, Checkbox determined that 
+the machine lacks the necessary audio devices to support the test.
+
+
+.. code-block:: none
+
+      ☑ : Hardware Manifest
+      ☐ : Check that at least one audio playback device exits
+      ☑ : Check that at least one audio capture device exists
+      
+After all the jobs are completed, a checklist will summarize the results of 
+each test.
+
+
+.. code-block:: none
+
+    file:///home/user/.local/share/checkbox-ng/submission_2023-07-25T07.53.41.800141.html
+    file:///home/user/.local/share/checkbox-ng/submission_2023-07-25T07.53.41.800141.junit.xml
+    file:///home/user/.local/share/checkbox-ng/submission_2023-07-25T07.53.41.800141.tar.xz
+  
+Checkbox collect all data related to the test and generates a **Test Reports** 
+locally.
+
+
+.. code-block:: none
+
+    Do you want to submit 'upload to certification' report?
+      y => yes
+      n => no
+
+Users would be asked whether they want to upload the results to the Canonical 
+:term:`Certification website`.
+
+Congrats! Now you have a basic understanding 
+of the test output.
+