Add note about redis server in wsl

[efcy]

This change adds a note about manually starting the redis server inside wsl. This is necessary because installing the redis-server package does not start it when systemd is not available.

Motivation and context

Multiple people ran into this problem and reported it on gitter. Also it's not obvious that you have to start it manually.

How has this been tested?

Manually

Checklist

• I submit my changes into the develop branch
• I have added description of my changes into CHANGELOG file
• I have updated the documentation accordingly
  - [ ] I have added tests to cover my changes
  - [ ] I have linked related issues (read github docs)
  - [ ] I have increased versions of npm packages if it is necessary (cvat-canvas,
  cvat-core, cvat-data and cvat-ui)

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)

[azhavoro]

@dvkruchinin Hi, could you please take a look at these issues:

1. Remark check is failed, but no artifacts were uploaded
2. Tests for 3D functionality are failed, but this PR cannot lead to this

[ActiveChooN]

@StellaASchlotter, hi, thanks for the contribution. Personally, I start redis inside a docker for WSL without the necessity to start service manually. So, can you add a note about this case?

[nmanovic]

It is a very long line. Markdown linter complains about that: https://github.com/openvinotoolkit/cvat/actions/runs/1387241296 (see artifacts on the page)

[nmanovic]

@StellaASchlotter , will you have time to improve the PR a little bit?

[efcy]

@StellaASchlotter , will you have time to improve the PR a little bit?

I will do it tomorrow.

[efcy]

I hope I addressed all remarks. Let me know if I should change anything.

[nmanovic]

@StellaASchlotter , great job! Thank you for your contributions.