Submit Softblues.io site to Gatsby Showcase (#22137)

Updated sites.yml to submit my website to the Gatsby Showcase

Author: Andriy Shabat

docs/sites.yml

@@ -10021,3 +10021,12 @@
     - Blog
   built_by: PJ
   built_by_url: "https://pjsachdev.me"
+- title: Softblues
+  main_url: https://softblues.io
+  url: https://softblues.io
+  description: >
+    We optimize your project costs and deliver outstanding results by applying relevant technology. Plus, we create our own effective products for businesses and developers all over the world.
+  categories:
+    - WordPress
+    - Portfolio
+    - Agency