fix: doc config and test-folders

tests/ddlonly/mddl_dc_difftable.test.sas

@@ -0,0 +1,19 @@
+/**
+  @file
+  @brief Difftable DDL test
+
+  <h4> SAS Macros </h4>
+  @li mddl_dc_difftable.sas
+  @li mf_existds.sas
+  @li mp_assert.sas
+
+**/
+
+
+%mddl_dc_difftable(libds=WORK.DIFFTABLE)
+
+%mp_assert(
+  iftrue=(%mf_existds(WORK.DIFFTABLE)=1),
+  desc=Checking table was created,
+  outds=work.test_results
+)