Add Colab Tutorial

[zytx121]

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Motivation

Add Colab Tutorial.

Modification

Please briefly describe what modification is made in this PR.

BC-breaking (Optional)

Does the modification introduce changes that break the back-compatibility of the downstream repos?
If so, please describe how it breaks the compatibility and how the downstream projects should modify their code to keep compatibility with this PR.

Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases here, and update the documentation.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. The documentation has been modified accordingly, like docstring or example tutorials.

[codecov-commenter]

Codecov Report

Merging #66 (2445646) into dev (dd40984) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev      #66   +/-   ##
=======================================
  Coverage   28.76%   28.76%           
=======================================
  Files         102      102           
  Lines        6571     6571           
  Branches      985      985           
=======================================
  Hits         1890     1890           
  Misses       4617     4617           
  Partials       64       64           

Flag	Coverage Δ
unittests	28.74% <ø> (ø)

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[yangxue0827]

LGTM

[jbwang1997]

LGTM

[ZwwWayne]

1. we should not use dev branch but should recommend users to use the released master branch
2. suggest renaming it as inference_demo.ipynb

[ZwwWayne]

Should we also teach users how to train the model on a new dataset?

[zytx121]

1. we should not use dev branch but should recommend users to use the released master branch
2. suggest renaming it as inference_demo.ipynb

There is a bug in the master branch that will cause an error when running the demo. This bug has been fixed in the dev branch. So currently only the dev branch can be used.

[zytx121]

Should we also teach users how to train the model on a new dataset?

OK, I will try it.

[jbwang1997]

The downloading command has been commented.

[zytx121]

1. we should not use dev branch but should recommend users to use the released master branch
2. suggest renaming it as inference_demo.ipynb

@ZwwWayne Since we added a section about how to train the model on a new dataset, should we rename it or not?