add xestrel

Author: YozoraKurage

source.json

@@ -16,7 +16,8 @@
     "githubRepos":[
         "YozoraKurage/DaerD",
         "YozoraKurage/YozoLab-Utils",
-        "YozoraKurage/Tabstep"
+        "YozoraKurage/Tabstep",
+        "YozoraKurage/xestrel"
     ],
     "packages":[
     ]