Added test case documentation generator

docs/test_cases/t20001.md

@@ -0,0 +1,103 @@
+# t20001 - Basic sequence diagram
+## Config
+```yaml
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t20001_sequence:
+    type: sequence
+    glob:
+      - ../../tests/t20001/t20001.cc
+    include:
+      namespaces:
+        - clanguml::t20001
+    exclude:
+      namespaces:
+        - clanguml::t20001::detail
+    using_namespace:
+      - clanguml::t20001
+    start_from:
+      - usr: "c:@N@clanguml@N@t20001@F@tmain#"
+    plantuml:
+      before:
+        - "' t20001 test sequence diagram"
+      after:
+        - 'note over "tmain()": Main test function'
+
+```
+## Source code
+```cpp
+#include <algorithm>
+#include <numeric>
+#include <vector>
+
+namespace clanguml {
+namespace t20001 {
+
+namespace detail {
+struct C {
+    auto add(int x, int y) { return x + y; }
+};
+}
+
+class A {
+public:
+    A() {}
+
+    int add(int x, int y) { return m_c.add(x, y); }
+
+    int add3(int x, int y, int z)
+    {
+        std::vector<int> v;
+        v.push_back(x);
+        v.push_back(y);
+        v.push_back(z);
+        auto res = add(v[0], v[1]) + v[2];
+        log_result(res);
+        return res;
+    }
+
+    void log_result(int r) {}
+
+private:
+    detail::C m_c{};
+};
+
+class B {
+public:
+    B(A &a)
+        : m_a{a}
+    {
+    }
+
+    int wrap_add(int x, int y)
+    {
+        auto res = m_a.add(x, y);
+        m_a.log_result(res);
+        return res;
+    }
+
+    int wrap_add3(int x, int y, int z)
+    {
+        auto res = m_a.add3(x, y, z);
+        m_a.log_result(res);
+        return res;
+    }
+
+private:
+    A &m_a;
+};
+
+int tmain()
+{
+    A a;
+    B b(a);
+
+    return b.wrap_add3(1, 2, 3);
+}
+}
+}
+
+```
+## Generated UML diagrams
+![t20001_sequence](./t20001_sequence.png "Basic sequence diagram")