refactor: mark iscomplete, isparameter as public

Author: AayushSabharwal

docs/src/API/variables.md

@@ -289,6 +289,7 @@ This metadata is used by the [`System`](@ref) constructor for automatically iden
 ```@docs
 ModelingToolkit.VariableType
 ModelingToolkit.MTKVariableTypeCtx
+ModelingToolkit.isparameter
 ```
 
 ## Miscellaneous metadata

src/ModelingToolkit.jl

@@ -343,7 +343,7 @@ export DynamicOptSolution
 @public VariableDescription, VariableInput, VariableIrreducible, VariableMisc
 @public VariableOutput, VariableStatePriority, VariableUnit, collect_scoped_vars!
 @public collect_var_to_name!, collect_vars!, eqtype_supports_collect_vars, hasdefault
-@public getdefault, setdefault
+@public getdefault, setdefault, iscomplete, isparameter
 
 for prop in [SYS_PROPS; [:continuous_events, :discrete_events]]
     getter = Symbol(:get_, prop)

src/parameters.jl

@@ -17,6 +17,11 @@ struct MTKVariableTypeCtx end
 
 getvariabletype(x, def = VARIABLE) = getmetadata(unwrap(x), MTKVariableTypeCtx, def)
 
+"""
+    $TYPEDEF
+
+Check if the variable contains the metadata identifying it as a parameter.
+"""
 function isparameter(x)
     x = unwrap(x)