[CDB-READER] Update _SpringData

docs/cdb/test_setup.rst

@@ -90,4 +90,5 @@ the temporary environment variable approach, open an MSYS2 MINGW64 shell, naviga
     tests/cable_data
     tests/cable_load
     tests/cable_result
+    tests/spring_data
     tests/truss_data

docs/cdb/tests/spring_data.rst

@@ -0,0 +1,25 @@
+SpringData
+----------
+
+Related test suite: ``test_spring_data.py``
+
+Expected CDB file name: ``SPRING_DATA.cdb``
+
+Runs with: SOFiSTiK 2025
+
+Version: 1
+
+.. code-block:: text
+
+    +PROG SOFIMSHA
+        HEAD GEOMETRY REV-1-SOF-2025
+        SYST 3D GDIR NEGZ GDIV 100
+        NODE NO 01 X 00.0 Y 0.0 Z +0.0
+        NODE NO 02 X 05.0 Y 0.0 Z -0.5
+        NODE NO 03 X 10.0 Y 0.0 Z -1.0
+
+        GRP 10 TITL 'GRP 1'
+            SPRI NO 1 NA 1 NE 2 CP 1.0 CT 2.5
+        GRP 20 TITL 'GRP 2'
+            SPRI NO 20 NA 2 DX 0.2 DY 0.3 DZ 1.0 CM 1.5
+    END