add ctime and ctime_r to docs

Author: zimirza

libc/docs/headers/time.rst

@@ -73,9 +73,9 @@ Implementation Status
 +---------------------+---------+---------+---------+-----------------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
 | clock_settime       |         |         |         |                 |         |         |         |         |         |         |         |         |         |
 +---------------------+---------+---------+---------+-----------------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
-| ctime               |         |         |         |                 |         |         |         |         |         |         |         |         |         |
+| ctime               | |check| | |check| |         |     |check|     |         |         |         |         |         |         |         |         |         |
 +---------------------+---------+---------+---------+-----------------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
-| ctime_r             |         |         |         |                 |         |         |         |         |         |         |         |         |         |
+| ctime_r             | |check| | |check| |         |     |check|     |         |         |         |         |         |         |         |         |         |
 +---------------------+---------+---------+---------+-----------------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
 | difftime            | |check| | |check| |         |     |check|     |         |         |         |         |         |         |         |         |         |
 +---------------------+---------+---------+---------+-----------------+---------+---------+---------+---------+---------+---------+---------+---------+---------+