update button asset to use github repo

Author: nullfunc

README.md

@@ -1,6 +1,6 @@
 # Node.js & Express
 
-[![1-click-deploy](https://defang.io/deploy-with-defang.svg)](https://portal.defang.dev/redirect?url=https%3A%2F%2Fgithub.com%2Fnew%3Ftemplate_name%3Dsample-nodejs-express-template%26template_owner%3DDefangSamples)
+[![1-click-deploy](https://raw.githubusercontent.com/DefangLabs/defang-assets/main/Logos/Buttons/SVG/deploy-with-defang.svg)](https://portal.defang.dev/redirect?url=https%3A%2F%2Fgithub.com%2Fnew%3Ftemplate_name%3Dsample-nodejs-express-template%26template_owner%3DDefangSamples)
 
 This Node.js application, built with Express.js, is designed to inspect and display detailed information about incoming HTTP requests. It supports all HTTP methods and provides insights into the request path, method, headers, query parameters, and body. Note alongside your project, you should also include a package.json file that includes the relevant metadata such as package dependencies, scripts, project verrsions so that the Dockerfile can install necessary dependencies.