Add general home configuration function and starship configuration

Signed-off-by: George Kaklamanos <gkaklas@gkaklas.gr>

home-manager/config.nix

@@ -0,0 +1,3 @@
+{pkgs, ...}: {
+  imports = [./starship.nix];
+}

home-manager/flake.nix

@@ -32,6 +32,7 @@
       inherit pkgs;
       modules = [
         ./home.nix
+        ./config.nix
         ./packages.nix
         ./flatpak.nix
         ./plasma/plasma.nix

home-manager/starship.nix

@@ -0,0 +1,42 @@
+{pkgs, ...}: {
+  programs.starship.enable = true;
+  programs.starship.enableFishIntegration = true;
+
+  programs.starship.settings = {
+    battery.disabled = false;
+    battery.charging_symbol = "⚡️ ";
+
+    time = {
+      disabled = false;
+      format = "🕙[$time ]($style)";
+      style = "bold #C51E3A"; # Cardinal red
+    };
+
+    hostname = {
+      format = "[$hostname ]($style)";
+      style = "bold #4CBB17"; # Kelly green
+      ssh_only = false;
+    };
+
+    username = {
+      format = "[$user@]($style)";
+      style_user = "bold #AFDBF5"; # Uranian blue
+      show_always = true;
+    };
+
+    git_branch = {
+      symbol = "";
+    };
+
+    cmd_duration = {
+      format = "[$duration ]($style)";
+      show_notifications = true;
+      style = "bold #E0115F"; # Ruby
+    };
+
+    python.format = "[$symbol$pyenv_prefix($version)(($virtualenv)) ]($style)";
+    rust.format = "[$symbol($version) ]($style)";
+    format = "$username$hostname$battery$time$jobs$git_branch$python$rust$cmd_duration$directory
+:> ";
+  };
+}