chore: update references to reflect application name change to DevHub

- Changed the live application link in README.md to point to the new URL.
- Updated the repository name in the Contact page to match the new branding.
- Revised comments in the JSON Viewer component to align with the updated application name.

src/page/contact/index.tsx

@@ -5,7 +5,7 @@ import React from "react"
  */
 export default function Contact() {
   const owner = "onixbyte"
-  const repo = "json-visualiser"
+  const repo = "dev-hub"
 
   const handleRedirect = (e: React.FormEvent<HTMLFormElement>) => {
     e.preventDefault()

src/page/json-viewer/index.tsx

@@ -3,7 +3,7 @@ import jp from "jsonpath"
 import JsonTreeNode from "@/components/json-tree-node"
 
 /**
- * JSON Viewer page component that displays the JSON Visualiser tool in DevLab.
+ * JSON Viewer page component that displays the JSON visualisation tool in DevLab.
  */
 export default function JsonViewer() {
   const initialData = {