docs: add nanbf16

Signed-off-by: Krishna Pandey <[email protected]>

Author: krishna2803

libc/docs/headers/math/index.rst

@@ -211,7 +211,7 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
 | modf             | |check|          | |check|         | |check|                | |check|              | |check|                |                        | 7.12.6.18              | F.10.3.18                  |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
-| nan              | |check|          | |check|         | |check|                | |check|              | |check|                |                        | 7.12.11.2              | F.10.8.2                   |
+| nan              | |check|          | |check|         | |check|                | |check|              | |check|                | |check|                | 7.12.11.2              | F.10.8.2                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+
 | nearbyint        | |check|          | |check|         | |check|                | |check|              | |check|                |                        | 7.12.9.3               | F.10.6.3                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+------------------------+----------------------------+