docs: add enterprise code channel offline install guide

server-tools/hololake-code-channel/jd-candidate/hlcc-bootstrap.py

@@ -488,6 +488,10 @@ def bootstrap() -> None:
         config_target = STATE_ROOT / "config" / "app.ini"
         shutil.copyfile(config_source, config_target)
         config_target.chmod(0o600)
+        custom_source = pathlib.Path(__file__).with_name("custom")
+        custom_target = STATE_ROOT / "data" / "custom"
+        if custom_source.is_dir():
+            shutil.copytree(custom_source, custom_target, dirs_exist_ok=True)
         set_status(stage="launching")
         log_path = STATE_ROOT / "logs" / "hlcc.log"
         log_handle = log_path.open("ab", buffering=0)