Pump action version number to 2.0.0

Author: tomtomsen

README.md

@@ -12,7 +12,7 @@ Basic usage with all options enabled:
 ```yaml
 
       - name: markdownlint-cli
-        uses: nosborn/github-action-markdown-cli@v1.1.1
+        uses: nosborn/github-action-markdown-cli@v2.0.0
         with:
           files: .
           config_file: ".markdownlint.yaml"