Updated test cases documentation

docs/test_cases/t00045.md

@@ -0,0 +1,60 @@
+# t00045 - Test case for root namespace handling
+## Config
+```yaml
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t00045_class:
+    type: class
+    glob:
+      - ../../tests/t00045/t00045.cc
+    exclude:
+      namespaces:
+        - std
+```
+## Source code
+File t00045.cc
+```cpp
+class A {
+};
+
+class AA {
+};
+
+namespace ns1 {
+
+class A {
+};
+
+namespace ns2 {
+
+class A {
+};
+
+class B : public A {
+};
+
+class C : public ns1::A {
+};
+
+class D : public ns1::ns2::A {
+};
+
+class E : public ::A {
+};
+
+class R {
+public:
+    A *a;
+    ns1::A *ns1_a;
+    ns1::ns2::A *ns1_ns2_a;
+    ::A *root_a;
+
+    void foo(::AA &aa) { (void)aa; }
+};
+}
+}
+
+```
+## Generated UML diagrams
+![t00045_class](./t00045_class.svg "Test case for root namespace handling")