distro-metadata: Add SHA256 placeholders for Ubuntu

Author: AdityaGarg8

docs/tools/distro-metadata.json

@@ -38,60 +38,68 @@
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-24.04-6.18.5-t2-noble.iso.00",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-24.04-6.18.5-t2-noble.iso.01",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-24.04-6.18.5-t2-noble.iso.02"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Ubuntu 25.10 - Questing Quokka",
       "iso": [
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-25.10-6.18.5-t2-questing.iso.00",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-25.10-6.18.5-t2-questing.iso.01",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-25.10-6.18.5-t2-questing.iso.02"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Kubuntu 24.04 - Noble Numbat",
       "iso": [
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/kubuntu-24.04-6.18.5-t2-noble.iso.00",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/kubuntu-24.04-6.18.5-t2-noble.iso.01",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/kubuntu-24.04-6.18.5-t2-noble.iso.02"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Kubuntu 25.10 - Questing Quokka",
       "iso": [
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/kubuntu-25.10-6.18.5-t2-questing.iso.00",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/kubuntu-25.10-6.18.5-t2-questing.iso.01",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/kubuntu-25.10-6.18.5-t2-questing.iso.02"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Ubuntu Unity 24.04 - Noble Numbat",
       "iso": [
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-unity-24.04-6.18.5-t2-noble.iso.00",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-unity-24.04-6.18.5-t2-noble.iso.01",
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-unity-24.04-6.18.5-t2-noble.iso.02"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Linux Mint - Cinnamon",
       "iso": [
         "https://github.com/t2linux/T2-Mint/releases/download/v6.18.5-1/linuxmint-22.3-cinnamon-6.18.5-t2-noble.iso.00",
         "https://github.com/t2linux/T2-Mint/releases/download/v6.18.5-1/linuxmint-22.3-cinnamon-6.18.5-t2-noble.iso.01"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Linux Mint - Mate",
       "iso": [
         "https://github.com/t2linux/T2-Mint/releases/download/v6.18.5-1/linuxmint-22.3-mate-6.18.5-t2-noble.iso.00",
         "https://github.com/t2linux/T2-Mint/releases/download/v6.18.5-1/linuxmint-22.3-mate-6.18.5-t2-noble.iso.01"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "Linux Mint - XFCE",
       "iso": [
         "https://github.com/t2linux/T2-Mint/releases/download/v6.18.5-1/linuxmint-22.3-xfce-6.18.5-t2-noble.iso.00",
         "https://github.com/t2linux/T2-Mint/releases/download/v6.18.5-1/linuxmint-22.3-xfce-6.18.5-t2-noble.iso.01"
-      ]
+      ],
+      "sha256": "TBD"
     },
     {
       "name": "NixOS Gnome",