Update README.md

README.md

@@ -24,4 +24,16 @@ jobs:
 Simple include a .gitleaks.toml in the root of your repo directory.
 
 ### NOTE!!!
-You must use `- uses: actions/checkout@v1` before the gitleaks-action step
+You must use `actions/checkout` before the gitleaks-action step. If you are using `actions/checkout@v2` you must specify a commit depth other than the default which is 1. 
+
+ex: 
+```
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: '0'
+    - name: gitleaks-action
+      uses: zricethezav/gitleaks-action@master
+```
+
+using a fetch-depth of '0' clones the entire history. If you want to do a more efficient clone, use '2', but that is not guaranteed to work with pull requests.