Replace the expired link with a backup Github repo

README.md

@@ -8,33 +8,37 @@ This repository is a compilation of well-written, step-by-step guides for re-cre
 
 It's a great way to learn.
 
-* [3D Renderer](#build-your-own-3d-renderer)
-* [Augmented Reality](#build-your-own-augmented-reality)
-* [BitTorrent Client](#build-your-own-bittorrent-client)
-* [Blockchain / Cryptocurrency](#build-your-own-blockchain--cryptocurrency)
-* [Bot](#build-your-own-bot)
-* [Command-Line Tool](#build-your-own-command-line-tool)
-* [Database](#build-your-own-database)
-* [Docker](#build-your-own-docker)
-* [Emulator / Virtual Machine](#build-your-own-emulator--virtual-machine)
-* [Front-end Framework / Library](#build-your-own-front-end-framework--library)
-* [Game](#build-your-own-game)
-* [Git](#build-your-own-git)
-* [Network Stack](#build-your-own-network-stack)
-* [Neural Network](#build-your-own-neural-network)
-* [Operating System](#build-your-own-operating-system)
-* [Physics Engine](#build-your-own-physics-engine)
-* [Programming Language](#build-your-own-programming-language)
-* [Regex Engine](#build-your-own-regex-engine)
-* [Search Engine](#build-your-own-search-engine)
-* [Shell](#build-your-own-shell)
-* [Template Engine](#build-your-own-template-engine)
-* [Text Editor](#build-your-own-text-editor)
-* [Visual Recognition System](#build-your-own-visual-recognition-system)
-* [Voxel Engine](#build-your-own-voxel-engine)
-* [Web Browser](#build-your-own-web-browser)
-* [Web Server](#build-your-own-web-server)
-* [Uncategorized](#uncategorized)
+- [Build your own \<insert-technology-here\>](#build-your-own-insert-technology-here)
+- [Tutorials](#tutorials)
+    - [Build your own `3D Renderer`](#build-your-own-3d-renderer)
+    - [Build your own `Augmented Reality`](#build-your-own-augmented-reality)
+    - [Build your own `BitTorrent Client`](#build-your-own-bittorrent-client)
+    - [Build your own `Blockchain / Cryptocurrency`](#build-your-own-blockchain--cryptocurrency)
+    - [Build your own `Bot`](#build-your-own-bot)
+    - [Build your own `Command-Line Tool`](#build-your-own-command-line-tool)
+    - [Build your own `Database`](#build-your-own-database)
+    - [Build your own `Docker`](#build-your-own-docker)
+    - [Build your own `Emulator / Virtual Machine`](#build-your-own-emulator--virtual-machine)
+    - [Build your own `Front-end Framework / Library`](#build-your-own-front-end-framework--library)
+    - [Build your own `Game`](#build-your-own-game)
+    - [Build your own `Git`](#build-your-own-git)
+    - [Build your own `Network Stack`](#build-your-own-network-stack)
+    - [Build your own `Neural Network`](#build-your-own-neural-network)
+    - [Build your own `Operating System`](#build-your-own-operating-system)
+    - [Build your own `Physics Engine`](#build-your-own-physics-engine)
+    - [Build your own `Programming Language`](#build-your-own-programming-language)
+    - [Build your own `Regex Engine`](#build-your-own-regex-engine)
+    - [Build your own `Search Engine`](#build-your-own-search-engine)
+    - [Build your own `Shell`](#build-your-own-shell)
+    - [Build your own `Template Engine`](#build-your-own-template-engine)
+    - [Build your own `Text Editor`](#build-your-own-text-editor)
+    - [Build your own `Visual Recognition System`](#build-your-own-visual-recognition-system)
+    - [Build your own `Voxel Engine`](#build-your-own-voxel-engine)
+    - [Build your own `Web Browser`](#build-your-own-web-browser)
+    - [Build your own `Web Server`](#build-your-own-web-server)
+    - [Uncategorized](#uncategorized)
+- [Contribute](#contribute)
+- [Origins \& License](#origins--license)
 
 ## Tutorials
 
@@ -261,7 +265,7 @@ It's a great way to learn.
 * [**C**: _Building a software and hardware stack for a simple computer from scratch_](https://www.youtube.com/watch?v=ZjwvMcP3Nf0&list=PLU94OURih-CiP4WxKSMt3UcwMSDM3aTtX) [video]
 * [**C**: _Operating Systems: From 0 to 1_](https://tuhdo.github.io/os01/)
 * [**C**: _The little book about OS development_](https://littleosbook.github.io/)
-* [**C**: _Roll your own toy UNIX-clone OS_](http://jamesmolloy.co.uk/tutorial_html/)
+* [**C**: _Roll your own toy UNIX-clone OS_](https://github.com/NateBrune/jamesmolloy.co.uk)
 * [**C**: _Kernel 101 – Let’s write a Kernel_](https://arjunsreedharan.org/post/82710718100/kernel-101-lets-write-a-kernel)
 * [**C**: _Kernel 201 – Let’s write a Kernel with keyboard and screen support_](https://arjunsreedharan.org/post/99370248137/kernel-201-lets-write-a-kernel-with-keyboard)
 * [**C**: _Build a minimal multi-tasking kernel for ARM from scratch_](https://github.com/jserv/mini-arm-os)