docs: Decap 3 annocement post (decaporg#6877)

Add Decap 3.0 annocement post

Author: martinjagodic

website/content/blog/decap-3.md

@@ -0,0 +1,45 @@
+---
+title: Decap 3.0
+description: >-
+  First release as Decap CMS is now available
+date: 2023-08-23T08:00:00.000Z
+author: Martin Jagodic
+twitter_image: /img/decap-3.png
+---
+We are happy to announce that the first release of Decap CMS is now available. It is released under 3.0 to honour the 2 major versions as the Netlify CMS.
+
+Decap on NPM: https://www.npmjs.com/package/decap-cms
+
+## Add to your site
+
+Via script tag in admin.html:
+
+```html
+<script src="https://unpkg.com/decap-cms@^3.0.0/dist/decap-cms.js"></script>
+```
+
+or via NPM:
+
+```bash
+npm install decap-cms-app
+```
+
+## Changes
+
+Decap 3.0 is very similar to Netlify CMS 2.10.192 (the last available version), and it's fully backwards compatible. 
+
+Notable changes are:
+- Renamed project: logo, name, packages, npm, and all other references to Netlify CMS
+- Updated Slate editor
+- Updated Webpack
+- Cypress: updated and all tests are working & passing again
+- Updated Typescript
+- Added Toastify notifications
+
+## Potential issues
+
+There was no beta phase as this is the first release, so there might be some issues that we didn't find. Please report them on Github.
+
+## Thanks
+
+Thanks to everyone in the community that waited patiently for so long. Thanks to all the comtributors and other engaged users that helped us in this transition period. Thanks to Netlify for creating this amazing project and for letting us continue it.