goldendict-ng/website/docs/howto/how to use .clang-format to format the code.md

Goal

the project has included a .clang-format as the code guideline.

How to use this file

CommandLine

Stash changes via git add files then git-clang-format

https://clang.llvm.org/docs/ClangFormat.html#git-integration

QtCreator:

Check the steps in the following webpage. https://doc.qt.io/qtcreator/creator-indenting-code.html#automatic-formatting-and-indentation

Visual Studio(Newer Version)

visual studio will automatically detect this file and apply the format guideline.

Fix warnings reported by SonarCloud

After PR submitted , a SonarCloud analysis will take place. Fix all the warnings introduced by your PR. Previous code may also have many warnings ,can be left alone.