Remove the Sequence encapsulation of variadic parameters (#276)

* Remove the `Sequence` encapsulation of variadic parameters
* Explicitly state that variadic parameters can take an arbitrary number of objects

Author: BvB93

spec/API_specification/creation_functions.md

@@ -304,9 +304,9 @@ Returns coordinate matrices from coordinate vectors.
 
 #### Parameters
 
--    **arrays**: _Sequence\[ <array> ]_
+-    **arrays**: _<array>_
 
-     -   one-dimensional arrays representing grid coordinates. Must have a numeric data type.
+     -   an arbitrary number of one-dimensional arrays representing grid coordinates. Must have numeric data types.
 
 -    **indexing**: _str_
 

spec/API_specification/data_type_functions.md

@@ -14,9 +14,9 @@ Broadcasts one or more arrays against one another.
 
 #### Parameters
 
--   **arrays**: _Sequence\[ <array> ]_
+-   **arrays**: _<array>_
 
-    -   arrays to broadcast.
+    -   an arbitrary number of to-be broadcasted arrays.
 
 #### Returns
 
@@ -134,9 +134,9 @@ If provided mixed dtypes (e.g., integer and floating-point), the returned dtype
 
 #### Parameters
 
--   **arrays_and_dtypes**: _Sequence\[ Union\[ <array>, <dtype> \] \]_
+-   **arrays_and_dtypes**: _Union\[ <array>, <dtype> \]_
 
-    -   input arrays and dtypes.
+    -   an arbitrary number of input arrays and/or dtypes.
 
 #### Returns