Add details doxygen command

Because the following documentation is details about the pass.

Author: thomasspriggs

src/assembler/remove_asm.h

@@ -12,7 +12,7 @@ Date:   December 2014
 /// \file
 /// Remove 'asm' statements by compiling them into suitable standard goto
 /// program instructions.
-///
+/// \details
 /// Inline assembly statements in the source program (in either gcc- or
 /// msc-style) are represented by instructions of kind `OTHER` with a `code`
 /// member of type `code_asmt` in the goto program.