modified parameter.json: units in keys and isogeometric elements

[div-tyg]

Changes:

• units in keys.
• Isogeometric elements
• new output mterics (no. of DOFs and max. displacement error at nodes).

[joergfunger]

looks almost good to me, I would significantly change/add a sensor configuration layout. I'm only not sure where to place that. We could either add it to the parameter.json, or we add that to a tool_specific parameter_file (since I'm not sure everyone will be able to use it. Or we add another sensor.json? Any ideas?

[joergfunger]

Make sure that all changes that are made here are actually transferred to the new repo, including the changes in the markdown files. @div-tyg please merge the branch into main yourself (and directly delete the branch - there is a button in github right after you have done the merge).