Update history.rst

Author: Evolutionary-Intelligence

docs/sphinx/source/history.rst

@@ -8,8 +8,8 @@ During Winter 2017, Qiqi Duan, when as a Ph.D. candidate at SUSTech, Shenzhen,
 Guangdong, China (joint with HIT, Harbin, Heilongjiang, China), chat with Hao
 Tong, as a Master candidate also in SUSTech, regarding the necessarity of an
 open-source library for evolutionary algorithms (EAs) and swarm-based
-optimizers. Clearly, it is a huge work to cover as many as well-established
-and newly-emerging versions and variants of EAs.
+optimizers (SOs). Clearly, it is a huge work to cover as many as
+well-established and newly-emerging versions and variants of EAs and SOs.