Update the function parameters in the API documentation

[ilkecan]

• nodejs is added under node_modules
• buildInputs is removed from node_modules and shell. The reason is, this is originally an parameter of mkDerivation and it is not handled any different from any other mkDerivation parameter inside those functions.
• Some parameters are reordered;
  • Mandatory parameters are moved to the top.
  • Otherwise parameters are ordered according to their order in the source code.

[gilligan]

Thanks!