docs(user): add query strings tutorial

[bssyousefi]

Summary of Changes

Fill in the placeholder for Query Strings in the documentation. The placeholder only existed on WSGI tutorial, so the proposed change is just about that part of the documentation.

Related Issues

475

Pull Request Checklist

This is just a reminder about the most common mistakes. Please make sure that you tick all appropriate boxes. But please read our contribution guide at least once; it will save you a few review cycles!

If an item doesn't apply to your pull request, check it anyway to make it apparent that there's nothing to do.

• [ ] Applied changes to both WSGI and ASGI code paths and interfaces (where applicable).
• [ ] Added tests for changed code.
• [ ] Prefixed code comments with GitHub nick and an appropriate prefix.
• [x] Coding style is consistent with the rest of the framework.
• [x] Updated documentation for changed code.
  • [ ] Added docstrings for any new classes, functions, or modules.
  • [ ] Updated docstrings for any modifications to existing code.
  • [x] Updated both WSGI and ASGI docs (where applicable).
  • [ ] Added references to new classes, functions, or modules to the relevant RST file under docs/.
  • [ ] Updated all relevant supporting documentation files under docs/.
  • [ ] A copyright notice is included at the top of any new modules (using your own name or the name of your organization).
  • [ ] Changed/added classes/methods/functions have appropriate versionadded, versionchanged, or deprecated directives.
• [ ] Changes (and possible deprecations) have towncrier news fragments under docs/_newsfragments/, with the file name format {issue_number}.{fragment_type}.rst. (Run towncrier --draft to ensure it renders correctly.)

If you have any questions to any of the points above, just submit and ask! This checklist is here to help you, not to deter you from contributing!

PR template inspired by the attrs project.

[bssyousefi]

I have a question regarding a part of the code.

 _IMAGE_NAME_PATTERN = re.compile(
            '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\.[a-z]{2,4}$'
        )

which I used from previous parts of the docs. the string used as the pattern will raise error in python. I guess we should use one of the following ways

 _IMAGE_NAME_PATTERN = re.compile(
            '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}.[a-z]{2,4}$'
        )
 _IMAGE_NAME_PATTERN = re.compile(
            r'[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\.[a-z]{2,4}$'
        )

However, I didn't try to fix it here and I thought that maybe I should first report it as an issue and then resolve it in another PR. Am I right or should I try the fix on this PR since it's a small change?

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (afe6c9f) to head (b49d829).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2239 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 63 63 Lines 7604 7604 Branches 1285 1285 ========================================= Hits 7604 7604 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[bssyousefi]

I have a question regarding a part of the code.

 _IMAGE_NAME_PATTERN = re.compile(
            '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\.[a-z]{2,4}$'
        )

which I used from previous parts of the docs. the string used as the pattern will raise error in python. I guess we should use one of the following ways

 _IMAGE_NAME_PATTERN = re.compile(
            '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}.[a-z]{2,4}$'
        )
 _IMAGE_NAME_PATTERN = re.compile(
            r'[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\.[a-z]{2,4}$'
        )

However, I didn't try to fix it here and I thought that maybe I should first report it as an issue and then resolve it in another PR. Am I right or should I try the fix on this PR since it's a small change?

@vytas7 Would you please also help me on this?

[bssyousefi]

@vytas7 I'm very sorry for the very long delay. I mistakenly thought that all the tests were passed and I didn't got time to get back to the project since I was a little bit busy. Thanks for you patience. I will be more available and responsible from now on.

[vytas7]

No worries, @bssyousefi :slightly_smiling_face: We are now focusing on getting 4.0 out the door, so your PR is not urgent. But it will be nice to have it done when ready.

[bssyousefi]

I guess it's ready. I've updated the tests for the example look