Update README-linux.md

Author: aso20455

docs/README-linux.md

@@ -9,7 +9,7 @@ sudo apt-get install libssl-dev libffi-dev autoconf automake libtool
 # ^ This is for Debian-like systems. TODO: Add more platforms
 
 sudo pacman -Sy libsecp256k1
-# ^ This is for ArchLinux system
+# ^ This is for ArchLinux systems
 
 sudo dnf install openssl-devel libffi-devel autoconf automake libtool
 # ^ This is for Fedora.