Remove arguments from api.md

Author: asterycs

docs/src/api.md

@@ -1,12 +1,12 @@
 # API Reference
 
 ```@docs
-@matrix(ids...)
-@vector(ids...)
-@scalar(ids...)
-derivative(expr, wrt::DiffMatic.Monomial)
-gradient(expr, wrt::DiffMatic.Monomial)
-jacobian(expr, wrt::DiffMatic.Monomial)
-hessian(expr, wrt::DiffMatic.Monomial)
-to_std(expr)
+@matrix
+@vector
+@scalar
+derivative
+gradient
+jacobian
+hessian
+to_std
 ```