Revert accidental change merged with PR #3433

[david-waterworth]

What does this PR do?

As requested by @Borda PR #3433 included an accidental change of docs/source/introduction_guide.rst line 300 .. testcode:: was changed to .. code-block:: python. This PR reverts this change.

.. testcode::
.. code-block:: python

Fixes: #3406

[awaelchli]

Rolls back accidentally change from testcode:: to code-block:: python in #3433

could you update the description? This PR seems to be about something else, I don't know what. A better title might also help :)

[david-waterworth]

Apologies not sure how that happened - looks like GitHub auto-filled the title from an old PR I submitted and I forgot to amend it. I've updated the description.

[awaelchli]

@david-waterworth I don't see any reverted changes. As per your description, you need to change the code block directive to .. testcode, correct?

[david-waterworth]

Yes I guess something got messed up when I created the pull request. I'll fix it tomorrow

[david-waterworth]

@awaelchli it looks ok to me - if you click on commits then the final (3rd one) line 300 is back to .. testcode::, but for some reason files changed isn't showing the correct diff.

I think this is because the original PR for this branch has been merged. I modified my branch with commit #3 and created this PR. So the files change diff is from before the 3 commits even though 2 have been merged?

Edit: Also if you look at the top of the page is says "david-waterworth wants to merge 3 commits into PyTorchLightning:master from david-waterworth:Fix-#3406"

[rohitgr7]

@david-alexander-white rebased with master. It's good now.

[codecov]

Codecov Report

Merging #3453 into master will increase coverage by 5%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #3453    +/-   ##
=======================================
+ Coverage      86%     90%    +5%     
=======================================
  Files         107     107            
  Lines        8063    8063            
=======================================
+ Hits         6896    7284   +388     
+ Misses       1167     779   -388