[DB-1792] Add server 26.0 (#938)

Author: timothycoleman

import/repos.json

@@ -8,6 +8,13 @@
     "currentBranch": "master",
     "repo": "https://github.com/kurrent-io/KurrentDB",
     "branches": [
+      {
+        "version": "v26.0",
+        "preview": true,
+        "name": "release/v26.0",
+        "relativePath": ["server"],
+        "startPage": "quick-start/"
+      },
       {
         "version": "v25.1",
         "name": "release/v25.1",