Add slides on std::format and std::print

[bernhardmgruber]

In C++20 we got std::format and in C++23 we will get std::print. Especially the latter is quite important for beginners, as it will offer a better alternative to std::cout. And the syntax is closer to python as well :)

[bernhardmgruber]

We discussed in a meeting yesterday that we could also mention libfmt as an alternative until users have those available.

[stale]

This issue or pull request has been automatically marked as stale because it has not had recent activity. Please manually close it, if it is no longer relevant, or ask for help or support to help getting it unstuck. Let me bring this to the attention of @klieret @wdconinc @michmx for now.

[stale]

This issue or pull request has been automatically marked as stale because it has not had recent activity. Please manually close it, if it is no longer relevant, or ask for help or support to help getting it unstuck. Let me bring this to the attention of @klieret @wdconinc @michmx for now.