Here it is a wishlist with features and ideas to improve the library. Note that features listed here are usually long term improvements or just describe a route to follow for the library. There are also some additional places to look for raylib improvements and ideas:
Current version of raylib is complete and functional but there is always room for improvements.
raylib 4.x
raylib 4.0
rnet
(#753) - DISCARDED - Use nbnet.raylib 3.0
raylib 2.5
raylib 2.0
raylib 1.8
raylib 1.7
raylib 1.6
raylib 1.5
raylib 1.4