feat(docs): Generate github source urls

docs/src/configuration-overview.md

@@ -5,6 +5,9 @@ I use [NixOS](https://nixos.org) and
 system and user configuration respectively. You can see what options I have
 added to configure the system and user configuration in the next chapters.
 
+The source repo is
+[configuration.nix](https://github.com/jalil-salame/configuration.nix).
+
 ## Table of Contents
 
 <!-- toc -->

docs/src/home-options.md

@@ -11,3 +11,5 @@ search](https://mipmip.github.io/home-manager-option-search/)
 ## Table of Contents
 
 <!-- toc -->
+
+## Options

docs/src/nixos-options.md

@@ -10,3 +10,5 @@ through [NixOS Options](https://search.nixos.org/options).
 ## Table of Contents
 
 <!-- toc -->
+
+## Options

docs/src/nvim-options.md

@@ -11,3 +11,5 @@ search](https://nixneovim.github.io/nixneovim-option-search/).
 ## Table of Contents
 
 <!-- toc -->
+
+## Options