[Doc] Emily/doc update

[chuneuny-emily]

This PR removes the duplicated and cyclical category context.

Summary

How to test

Checklist

• I submit my changes into the develop branch
• I have added description of my changes into CHANGELOG
• I have updated the documentation accordingly
• I have added tests to cover my changes
• I have linked related issues

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below)

# Copyright (C) 2021 Intel Corporation
#
# SPDX-License-Identifier: MIT

[codecov-commenter]

Codecov Report

Base: 78.26% // Head: 78.25% // Decreases project coverage by -0.01% ⚠️

Coverage data is based on head (984b331) compared to base (9b32c05).
Patch has no changes to coverable lines.

Additional details and impacted files

@@                 Coverage Diff                 @@
##           releases/v1.0.0     #822      +/-   ##
===================================================
- Coverage            78.26%   78.25%   -0.01%     
===================================================
  Files                  184      184              
  Lines                23563    23563              
  Branches              4880     4880              
===================================================
- Hits                 18442    18440       -2     
- Misses                4028     4029       +1     
- Partials              1093     1094       +1     

Flag	Coverage Δ
macos-11_Python-3.8	?
ubuntu-20.04_Python-3.8	78.24% <ø> (ø)
windows-2019_Python-3.8	78.18% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
datumaro/plugins/synthetic_data/utils.py	83.33% <0.00%> (-1.67%)	⬇️

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[yunchu]

please remove "develop" target branch from the list.

[chuneuny-emily]

I see.

[vinnamkim]

LGTM.