Documentation about Functional algorithms needs to be updated

[tmadlener]

The documentation about the Gaudi Functional usage in Key4hep (see here is still using Gaudi::Functional algorithms, when they should be pointing towards the k4FWCore variants of them. At least they should be the default that people go to. There is room for also mentioning that Gaudi::Functionals also work, but there the differences need to be explicitly stated.

[m-fila]

I'm slowly rewriting the docs on writing algorithms

[tmadlener]

Adding things to do here instead of opening new issues. The current documentation is also missing an example of how to declare a property for a functional algorithm.

[tmadlener]

@m-fila does it make sense for me to do this (or maybe continue from where you currently are)? Or are you close to being finished?

[m-fila]

Yes please feel free to take over, I'm too busy with other things and won't make it before the tutorials session. Sorry for the confusion