message: Fix missing doxygen link to Rust docs
diff: title="Use in Lua"/>
  <tab type="user" url="@ref flatbuffers_guide_use_lobster"
  title="Use in Lobster"/>
  + <tab type="user" url="@ref flatbuffers_guide_use_rust"
  + title="Use in Rust"/>
  <tab type="user" url="@ref flexbuffers"
  title="Schema-less version"/>
  <tab type="usergroup" url="" title="gRPC">
  