clang-format section added to the coding style guide

[Ahmad Samir]

Thanks to Alexander Lohnau, there is now a section in the KF coding style that explains about the 
usage of clang-format in the Frameworks:
https://community.kde.org/Policies/Frameworks_Coding_Style#Clang-format_automatic_code_formatting

including tips and tricks (mainly to trick clang-format so that it doesn't mangle your code)


Have a good day. :)

-- 
Ahmad Samir