From d649a291c3b26572b46fef8526ebb2bdfaf2ac3f Mon Sep 17 00:00:00 2001
From: Juanito Fatas <katehuang0320@gmail.com>
Date: Mon, 17 Feb 2020 20:33:01 +0900
Subject: [PATCH] Add suggestion when run on single platform

---
 README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/README.md b/README.md
index 392f634..4cca252 100644
--- a/README.md
+++ b/README.md
@@ -120,6 +120,7 @@ You can cache the installed gems with these two steps:
         bundle install --jobs 4 --retry 3
 ```
 
+When using a single OS, replace `${{ matrix.os }}` with the OS.  
 When using a single job with a Ruby version, replace `${{ matrix.ruby }}` with the Ruby version.  
 When using `.ruby-version`, replace `${{ matrix.ruby }}` with `${{ hashFiles('.ruby-version') }}`.  
 When using `.tool-versions`, replace `${{ matrix.ruby }}` with `${{ hashFiles('.tool-versions') }}`.