Fix minor typo (actions#130)

ffe4 · web-flow · commit 51d2bf1911fa · 2020-08-31T15:45:09.000+02:00
diff --git a/README.md b/README.md
@@ -94,7 +94,7 @@ jobs:
 
 ```
 
-Download and set up a accurate pre-release version of Python:
+Download and set up an accurate pre-release version of Python:
 ```yaml
 steps:
 - uses: actions/checkout@v2
