Update the main images to overview page in profiling tutorial.

[qiuminxu]

• Motivation for features / changes
  Update the images from scalar plugin to overview page to have a better show case of our tools.

• Technical description of changes

• Screenshots of UI changes

• Detailed steps to verify changes work correctly (as executed by you)

• Alternate designs / implementations considered

[review-notebook-app]

Check out this pull request on 

You'll be able to see Jupyter notebook diff and discuss changes. Powered by ReviewNB.

[wchargin]

The notebook file has a very large diff (9.8 MB) that appears to remove
the cached output cells entirely. Could you please fix the diff such
that it only includes the desired changes so that we can review it?

[qiuminxu]

The cached output cells should be removed (that shouldn't be checked in). If you check reviewnb, the diff should be easy to see.
https://app.reviewnb.com/tensorflow/tensorboard/pull/3372/files/

[wchargin]

Okay, if removing the cached cells is intentional, that’s fine (and
consistent with the rest of our docs), but could you please do so in a
separate pull request? I’m not comfortable relying on a third-party
loginwalled tool to accurately represent the diff of a commit that’s
merged into the repository history: we often need to call attention to
parts of the notebook source that are hidden by ReviewNB. It also
doesn’t seem right that a PR called “Minor updates to profiling
tutorial” should contain such a large change.

[qiuminxu]

Okay, I sent out another PR to clean up the output. PTAL.
#3381

[qiuminxu]

Thanks for reviewing. I've rebased this PR against #3381.

[wchargin]

Thank you! This is much clearer.