Add support for header tags in Javadoc

plugins/base/src/main/kotlin/translators/psi/parsers/JavadocParser.kt

@@ -421,6 +421,9 @@ class JavadocParser(
                         parsed
                     }
                 }
+                "h1" -> ifChildrenPresent { H1(children) }
+                "h2" -> ifChildrenPresent { H2(children) }
+                "h3" -> ifChildrenPresent { H3(children) }
                 else -> listOf(Text(body = element.ownText()))
             }
         }

plugins/base/src/test/kotlin/parsers/JavadocParserTest.kt

@@ -349,4 +349,51 @@ class JavadocParserTest : BaseAbstractTest() {
             }
         }
     }
+
+    @Test
+    fun `header tags are handled properly`() {
+        val source = """
+            |/src/main/kotlin/test/Test.java
+            |package example
+            |
+            | /**
+            | * An example of using the header tags
+            | * <h1>A header</h1>
+            | * <h2>A second level header</h2>
+            | * <h3>A third level header</h3>
+            | */
+            | public class Test  {}
+            """.trimIndent()
+        testInline(
+            source,
+            configuration,
+        ) {
+            documentablesCreationStage = { modules ->
+                val docs = modules.first().packages.first().classlikes.single().documentation.first().value
+                val root = docs.children.first().root
+
+                kotlin.test.assertEquals(
+                    listOf(
+                        P(children = listOf(Text("An example of using the header tags "))),
+                        H1(
+                            listOf(
+                                Text("A header")
+                            )
+                        ),
+                        H2(
+                            listOf(
+                                Text("A second level header")
+                            )
+                        ),
+                        H3(
+                            listOf(
+                                Text("A third level header")
+                            )
+                        )
+                    ),
+                    root.children
+                )
+            }
+        }
+    }
 }