Update doc/specs/stdlib_linalg.md

Co-authored-by: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>

Author: perazz

doc/specs/stdlib_linalg.md

@@ -1583,7 +1583,7 @@ matrix norms are computed over specified dimensions.
 
 ### Arguments
 
-`a`: Shall be a rank-n `real` or `complex` array containing the data, where n ³ 2. It is an `intent(in)` argument.
+`a`: Shall be a rank-n `real` or `complex` array containing the data, where n >= 2. It is an `intent(in)` argument.
 
 `order` (optional): Shall be an `integer` value or a `character` flag that specifies the norm type, as follows. It is an `intent(in)` argument.