docs: Refine documentation for clarity and consistency

[AminMemariani]

• Improved grammar and clarity in CONTRIBUTING.md, README.md, and various documentation files.
• Standardized phrasing for properties in chart data classes across documentation.
• Enhanced descriptions for touch handling and tooltip functionalities in scatter, pie, and radar charts.
• Corrected minor typographical errors and formatting issues throughout the documentation.

[imaNNeo]

Thank you, it looks good to me.
But now there are some conflicts. (Maybe because of your changes in other branches).

So please update your branch, then we can merge it!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.00%. Comparing base (9f74754) to head (6042278).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2038   +/-   ##
=======================================
  Coverage   93.00%   93.00%           
=======================================
  Files          50       50           
  Lines        3917     3917           
=======================================
  Hits         3643     3643           
  Misses        274      274           

Flag	Coverage Δ
flutter	93.00% <ø> (ø)

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[AminMemariani]

Thank you, it looks good to me. But now there are some conflicts. (Maybe because of your changes in other branches).

So please update your branch, then we can merge it!

You are welcome. Although the branch was updated, there were pipeline constraints that were blocking my commits, so I had to fix them.

[imaNNeo]

Oh sorry, I made some changes in #2057
So it seems there are some conflicts now.

[imaNNeo]

I see some changes in our unit tests.
Can you please revert them and open a new PR for them to keep this PR's scope only for the documentation?

[AminMemariani]

I see some changes in our unit tests.
Can you please revert them and open a new PR for them to keep this PR's scope only for the documentation?

The 9 test commits are dropped from the branch. they're still reachable via reflog locally (HEAD was 6042278)

[imaNNeo]

Thanks for your contribution!