* Bold project documentation link in README
* Add constexpr to trivial Atomics
According to https://en.cppreference.com/cpp/atomic/atomic/atomic the constructors of atomics should be constexpr. This change marks (at least for the trivial types) the constructor as constexpr.
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Co-authored-by: John Wellbelove <jwellbelove@users.noreply.github.com>
Co-authored-by: Roland Reichwein <Roland.Reichwein@bmw.de>