change checkout version in the docs

README.md

@@ -23,7 +23,7 @@ Here is a quick example of how to install this action in any workflow:
 
 ```yaml
 # checkout the repository (required for this Action to work)
-- uses: actions/checkout@v3
+- uses: actions/checkout@v4
 
 # validate JSON and YAML files
 - name: json-yaml-validate
@@ -83,7 +83,7 @@ jobs:
   json-yaml-validate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: json-yaml-validate
         id: json-yaml-validate
@@ -111,7 +111,7 @@ jobs:
   json-yaml-validate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: json-yaml-validate
         id: json-yaml-validate
@@ -152,7 +152,7 @@ Here is an example of how to use this feature:
 
 ```yaml
 # checkout the repository
-- uses: actions/checkout@v3
+- uses: actions/checkout@v4
 
 - name: json-yaml-validate
   uses: GrantBirki/[email protected] # replace with the latest version
@@ -285,7 +285,7 @@ If the file path to your `exclude_file` is `exclude.txt`, you would set the `exc
 
 ```yaml
 # checkout the repository
-- uses: actions/checkout@v3
+- uses: actions/checkout@v4
 
 - name: json-yaml-validate
   uses: GrantBirki/[email protected] # replace with the latest version