Avoid trimming non whitespace characters.

Rustc already removes all leading `/` symbols during the conversion
from doc-comments into annotations. Any additional trimming of non
whitespace characters just reduces the formatting flexibility of a
comment.

... fixes #374

tests/expectations/documentation.cpp

@@ -13,7 +13,15 @@ extern "C" {
 /// # Hint
 ///
 /// Always ensure that everything is properly documented, even if you feel lazy.
-/// Sometimes** it is also helpful to include some markdown formatting.
+/// **Sometimes** it is also helpful to include some markdown formatting.
+///
+/// ////////////////////////////////////////////////////////////////////////////
+///
+/// # Attention
+///
+/// Rust is going to trim all leading `/` symbols. If you want to use them as a
+/// marker you need to add at least a single whitespace inbetween the tripple
+/// slash doc-comment marker and the rest.
 void root();
 
 } // extern "C"