update readme

README.md

@@ -64,7 +64,7 @@ DocuSeal is an open source platform that provides secure and efficient digital d
 
 |Heroku|Railway|
 |:--:|:---:|
-| [<img alt="Deploy on Heroku" src="https://www.herokucdn.com/deploy/button.svg" height="40">](https://heroku.com/deploy?template=https://github.com/docusealco/docuseal-heroku) | [<img alt="Deploy on Railway" src="https://railway.app/button.svg" height="40">](https://railway.app/template/IGoDnc?referralCode=ruU7JR)|
+| [<img alt="Deploy on Heroku" src="https://www.herokucdn.com/deploy/button.svg" height="40">](https://heroku.com/deploy?template=https://github.com/docusealco/docuseal-heroku) | [<img alt="Deploy on Railway" src="https://railway.app/button.svg" height="40">](https://railway.com/deploy/IGoDnc?referralCode=ruU7JR)|
 |**DigitalOcean**|**Render**|
 | [<img alt="Deploy on DigitalOcean" src="https://www.deploytodo.com/do-btn-blue.svg" height="40">](https://cloud.digitalocean.com/apps/new?repo=https://github.com/docusealco/docuseal-digitalocean/tree/master&refcode=421d50f53990) | [<img alt="Deploy to Render" src="https://render.com/images/deploy-to-render-button.svg" height="40">](https://render.com/deploy?repo=https://github.com/docusealco/docuseal-render)