Update Checkout action version

Author: saerosV

README.md

@@ -68,7 +68,7 @@ Don't want to use `.github/ISSUE_TEMPLATE.md`? You can pass an input pointing th
 
 ```yaml
 steps:
-  - uses: actions/checkout@v2
+  - uses: actions/checkout@v3
   - uses: JasonEtco/create-an-issue@v2
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -82,7 +82,7 @@ Want to use Action logic to determine who to assign the issue to, to assign a mi
 
 ```yaml
 steps:
-  - uses: actions/checkout@v2
+  - uses: actions/checkout@v3
   - uses: JasonEtco/create-an-issue@v2
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}