fix: typo in bitswap spec header

Author: aschmahmann

BITSWAP.md

@@ -1,12 +1,12 @@
 # ![](https://img.shields.io/badge/status-wip-orange.svg?style=flat-square) Bitswap
 
-**Authors(s)**:
+**Author(s)**:
 - Adin Schmahmann
 - David Dias
 - Jeromy Johnson
 - Juan Benet
 
-**Maintainers(s)**:
+**Maintainer(s)**:
 
 * * *