fix: update heading styles for consistency across documentation

Author: ErwanDecoster

src/overview/helloWorld.md

@@ -13,7 +13,7 @@ import InfoIcon from '../components/InfoIcon.vue'
 > Reading time 🕒 2 mins
 
 <div class="bg-gradient-to-r from-[#fcd15a] to-[#ffad4d] rounded-[6px] px-8 pb-4 text-gray-800 max-w-3xl mx-auto mb-6">
-  <h2 class="text-2xl font-bold mt-0 border-none">Start Your Web3 Privacy Journey</h2>
+  <h2 class="text-2xl font-bold mt-0 border-none!">Start Your Web3 Privacy Journey</h2>
   <p>And learn how to build Privacy-preserving decentralized applications (dApps) with iExec in this interactive guide.</p>
   <div class="mt-6 flex items-center gap-4">
     <span class="bg-gray-900 text-white px-4 py-2 rounded-full font-medium">☕ 30 minutes journey</span>

src/overview/helloWorld/1-overview.md

@@ -11,7 +11,7 @@ description:
 > Reading time 🕒 8 mins
 
 <div class="bg-gradient-to-r from-[#fcd15a] to-[#ffad4d] rounded-[6px] px-8 pb-4 text-gray-800 max-w-3xl mx-auto mb-6">
-  <h2 class="text-2xl font-bold mt-0 border-none">Let's start with the basics</h2>
+  <h2 class="text-2xl font-bold mt-0 border-none!">Let's start with the basics</h2>
   <p>and explore how iExec can help you build Privacy-preserving applications and securely manage sensitive data.</p>
 </div>
 

src/overview/helloWorld/2-protectData.md

@@ -7,7 +7,7 @@
 > Reading time: 6 minutes
 
 <div class="bg-gradient-to-r from-[#fcd15a] to-[#ffad4d] rounded-[6px] px-8 pb-4 text-gray-800 max-w-3xl mx-auto mb-6">
-  <h2 class="text-2xl font-bold mt-0 border-none">Time to get practical</h2>
+  <h2 class="text-2xl font-bold mt-0 border-none!">Time to get practical</h2>
   <p>Let's follow Alice as she learns how to protect her data using DataProtector on Bob's dApp, our developer tool for protecting data creation and management.</p>
 </div>
 

src/overview/helloWorld/3-buildIApp.md

@@ -7,7 +7,7 @@ import InfoIcon from '../../components/InfoIcon.vue'
 </script>
 
 <div class="bg-gradient-to-r from-[#fcd15a] to-[#ffad4d] rounded-[6px] px-8 pb-4 text-gray-800 max-w-3xl mx-auto mb-6">
-  <h2 class="text-2xl font-bold mt-0 border-none">Time to build!</h2>
+  <h2 class="text-2xl font-bold mt-0 border-none!">Time to build!</h2>
   <p>Let's build an iApp that can process protected data in a secure environment using the <a href="../../tools/iapp-generator" target="_blank">iExec iApp generator tool</a>. This tool helps you create, test and deploy iApps with just a few commands.</p>
 </div>
 

src/overview/helloWorld/4-manageDataAccess.md

@@ -11,7 +11,7 @@
 > Reading time 🕒 6 mins
 
 <div class="bg-gradient-to-r from-[#fcd15a] to-[#ffad4d] rounded-[6px] px-8 pb-4 text-gray-800 max-w-3xl mx-auto mb-6">
-  <h2 class="text-2xl font-bold mt-0 border-none">Control Your Data</h2>
+  <h2 class="text-2xl font-bold mt-0 border-none!">Control Your Data</h2>
   <p>Alice will learn how to grant access to her protected data and manage who can use it.</p>
 </div>
 

src/overview/helloWorld/5-bonusChapter.md

@@ -8,7 +8,7 @@ import Button from '../../components/ui/Button.vue';
 > Reading time 🕒 4 mins
 
 <div class="bg-gradient-to-r from-[#fcd15a] to-[#ffad4d] rounded-[6px] px-8 pb-4 text-gray-800 max-w-3xl mx-auto mb-6">
-  <h2 class="text-2xl font-bold mt-0 border-none">Congratulations!</h2>
+  <h2 class="text-2xl font-bold mt-0 border-none!">Congratulations!</h2>
   <p class="m-0!">You've successfully completed the Hello World journey and learned how to protect data, deploy iApps, and manage data access. Now it's time to claim your rewards! 🏆</p>
 </div>