Merge pull request #2513 from szarnyasg/update-bitstring-docs

Update description of bitstring_agg() functions

docs/sql/functions/bitstring.md

@@ -49,8 +49,8 @@ These aggregate functions are available for `BIT` type.
 | `bit_and(arg)` |Returns the bitwise AND operation performed on all bitstrings in a given expression. | `bit_and(A)` |
 | `bit_or(arg)` |Returns the bitwise OR operation performed on all bitstrings in a given expression.  | `bit_or(A)` |
 | `bit_xor(arg)` |Returns the bitwise XOR operation performed on all bitstrings in a given expression. | `bit_xor(A)` |
-| `bitstring_agg(arg, min, max)` |Returns a bitstring with bits set for each distinct value. | `bitstring_agg(A, 1, 42)` |
-| `bitstring_agg(arg)` |Returns a bitstring with bits set for each distinct value. | `bitstring_agg(A)` |
+| `bitstring_agg(arg, min, max)` |Returns a bitstring with bits set for each distinct position defined in `arg`. All positions must be within the range [`min`, `max`] or an "Out of Range Error" will be thrown. | `bitstring_agg(A, 1, 42)` |
+| `bitstring_agg(arg)` |Returns a bitstring with bits set for each distinct position defined in `arg`. | `bitstring_agg(A)` |
 
 ### Bitstring Aggregation