Add documentation for legacy apis

[alikindsys]

[alikindsys]

Past me, please define what are "legacy apis", because depending on the definition the branch can be already merged and this issue dies.

[wffirilat]

This likely refers to Systems and SisbaseConfig (plus CustomConfig). These are still mostly undocumented, at least in the code. Some articles show how to use them, but code documentation is good too.

[alikindsys]

Thanks for clearing that up, that was it actually. 44-legacy-docs should be renamed to website then, since it only changes that. By that metric it doesn't actually fix the proposed issue.

That branch actually has some nice stuff there related to the website and that could be of use.

[wffirilat]

Any reason to not add website docs and code docs on the same issue? if there is, then do the rename, otherwise just keep it how it is and we'll merge after code docs are added

[alikindsys]

Not really now that i think about it.