Remove docstrings from parameter definitions in `runtime/*/params.rs`

[maltekliemann]

We're double/triple/quadruple-booking the docstrings of the parameters in the runtime definitions. This is unmaintainable and quite frankly very hard to read. Let's keep the docstrings for parameters in the pallet definitions.

[maltekliemann]

This is a won't fix. We want the docstrings to be there so that each runtime is documented separately. I'm leaving this open because the double/triple/quadruple-booking that we're doing to achieve this is not good. If you know a way of solving this problem, let us know.

[Chralt98]

We want the docstrings to be there so that each runtime is documented separately

Then just document inside each runtime what is actually different. And don't document what already is documented inside the pallet configuration parameter doc string.

[maltekliemann]

Then just document inside each runtime what is actually different.

This.