Add doc_markdown checks

Author: blyxyas

tests/ui/doc_errors.rs

@@ -82,6 +82,29 @@ impl Struct1 {
         unimplemented!();
     }
 
+    /**
+    # Errors
+    This is sufficiently documented.
+
+    This function is a test for this lint's capabilities with other
+    lints, such as `doc_markdown`
+    std::str;
+    */
+    pub fn pub_method_block_errors_header_doc_markdown() -> Result<(), ()> {
+        unimplemented!();
+    }
+
+    /**
+    This is not sufficiently documented.
+
+    This function is also a test for this lint's capabilities with other
+    lints, such as `doc_markdown`
+    std::str;
+    */
+    pub fn pub_method_missing_block_errors_header_doc_markdown() -> Result<(), ()> {
+        unimplemented!();
+    }
+
     /// # Errors
     /// A description of the errors goes here.
     pub async fn async_pub_method_with_errors_header() -> Result<(), ()> {

tests/ui/doc_errors.stderr

@@ -45,8 +45,14 @@ LL |     pub fn pub_method_missing_block_errors_header() -> Result<(), ()> {
 error: docs for function returning `Result` missing `# Errors` section
   --> $DIR/doc_errors.rs:104:5
    |
+LL |     pub fn pub_method_missing_block_errors_header_doc_markdown() -> Result<(), ()> {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: docs for function returning `Result` missing `# Errors` section
+  --> $DIR/doc_errors.rs:127:5
+   |
 LL |     fn trait_method_missing_errors_header() -> Result<(), ()>;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 9 previous errors