docs: update changelogs for v0.5.15 and v0.5.16 with new features and security fixes

docs/src/pages/changelog/2024-12-30-jan-new-privacy.mdx

@@ -1,7 +1,7 @@
 ---
 title: "Jan gives you full control over your privacy"
 version: 0.5.12
-description: "Improved Privacy settings to give full control over analytics."
+description: "Improved Privacy settings to give full control over analytics"
 date: 2024-12-30
 ogImage: "/assets/images/changelog/jan-v0.5.12.gif"
 ---

docs/src/pages/changelog/2025-01-06-key-issues-resolved.mdx

@@ -2,13 +2,13 @@
 title: "A few key issues have been solved!"
 version: 0.5.13
 description: "Jan v0.5.13 is here: A few key issues have been solved."
-date: 2024-01-06
+date: 2025-01-06
-ogImage: "/assets/images/changelog/jan-v0-5-13.gif"
+ogImage: "/assets/images/changelog/jan-v0-5-13.jpg"
 ---
 
 import ChangelogHeader from "@/components/Changelog/ChangelogHeader"
 
-<ChangelogHeader title= "Jan v0.5.13: A few key issues have been solved!" date="2024-01-06" ogImage= "/assets/images/changelog/jan-v0-5-13.gif"  />
+<ChangelogHeader title= "Jan v0.5.13: A few key issues have been solved!" date="2025-01-06" ogImage= "/assets/images/changelog/jan-v0-5-13.jpg"  />
 
 👋 Jan v0.5.13 is here: A few key issues have been solved!
 

docs/src/pages/changelog/2025-01-23-deepseek-r1-jan.mdx

@@ -2,13 +2,13 @@
 title: "Run DeepSeek R1 Distills error-free!"
 version: 0.5.14
 description: "Jan v0.5.14 is out: Run DeepSeek R1 Distills error-free!"
-date: 2024-01-23
+date: 2025-01-23
-ogImage: "/assets/images/changelog/jan-v0-5-14-deepseek-r1.gif"
+ogImage: "/assets/images/changelog/jan-v0-5-14-deepseek-r1.jpg"
 ---
 
 import ChangelogHeader from "@/components/Changelog/ChangelogHeader"
 
-<ChangelogHeader title= "Jan v0.5.14: Run DeepSeek R1 Distills error-free!" date="2024-01-23" ogImage= "/assets/images/changelog/jan-v0-5-14-deepseek-r1.gif"  />
+<ChangelogHeader title= "Jan v0.5.14: Run DeepSeek R1 Distills error-free!" date="2024-01-23" ogImage= "/assets/images/changelog/jan-v0-5-14-deepseek-r1.jpg"  />
 
 👋 Jan v0.5.14 is out: Run DeepSeek R1 Distills error-free!
 

docs/src/pages/changelog/2025-02-18-advanced-llama.cpp-settings.mdx

@@ -0,0 +1,28 @@
+---
+title: "You can now tweak llama.cpp settings, and add any cloud model!"
+version: 0.5.15
+description: "Jan v0.5.15 is out: Advanced llama.cpp settings and cloud model support"
+date: 2025-02-18
+ogImage: "/assets/images/changelog/jan-v0-5-15-llamacpp-settings.jpg"
+---
+
+import ChangelogHeader from "@/components/Changelog/ChangelogHeader"
+
+<ChangelogHeader title="Jan v0.5.15: You can now tweak llama.cpp settings, and add any cloud model!" date="2024-02-18" ogImage="/assets/images/changelog/jan-v0-5-15-llamacpp-settings.jpg" />
+
+👋 Jan v0.5.15 is out with exciting new features and improvements!
+
+## Highlights 🎉
+
+- Improved llama.cpp settings for better model control and performance
+- Install and use any cloud model seamlessly
+- Enhanced hardware controls for better resource management
+- New models supported:
+  - DeepSeek AI
+  - Google Gemini
+  - OpenAI o3-mini
+  - R1 distills
+
+Update your Jan or [download the latest](https://jan.ai/).
+
+For more details, see the [GitHub release notes](https://github.com/janhq/jan/releases/tag/v0.5.15).

docs/src/pages/changelog/2025-03-14-jan-security-patch.mdx

@@ -0,0 +1,29 @@
+---
+title: "Security fixes and UI improvements"
+version: 0.5.16
+description: "Jan v0.5.16 is out: Security fixes and major improvements to Model Hub and chat experience"
+date: 2025-03-14
+ogImage: "/assets/images/changelog/jan-v0-5-16-security-patch.jpg"
+---
+
+import ChangelogHeader from "@/components/Changelog/ChangelogHeader"
+
+<ChangelogHeader title="Jan v0.5.16: Security fixes and UI improvements" date="2025-03-14" ogImage="/assets/images/changelog/jan-v0-5-16-security-patch.jpg" />
+
+👋 Jan v0.5.16 is out: Security fixes (found in Cortex) and a few improvements!
+
+## Highlights 🎉
+
+- Redesigned Model Hub for better user experience
+- Faster chat response times
+- Cleaner layout and improved model picker
+- New model support:
+  - GPT-4.5 preview
+  - Claude 3.7 Sonnet
+  - Gemma 3
+
+⚠️ Important: This release includes critical security fixes. We'll share more details about these security improvements soon.
+
+Update your Jan or [download the latest](https://jan.ai/).
+
+For more details, see the [GitHub release notes](https://github.com/janhq/jan/releases/tag/v0.5.16).