Add test file

tool/rawstr4c/test/fixture/test-inherited-config.md

@@ -0,0 +1,28 @@
+- prefix = `ROOT`
+- keep-prefix = `true`
+
+```c
+root code;
+```
+
+# Level 1
+
+- prefix = `L1`
+
+```c
+level1 code;
+```
+
+## Level 2
+
+```c
+level2 code;
+```
+
+### Level 3
+
+- prefix = `L3`
+
+```c
+level3 code;
+```