Fix typos in usage/comments; Make rust generator respect to --filenam… (#6342)

* Fix typos in usage/comments; Make rust generator respect to --filename-suffix

* run clang format

src/idl_parser.cpp

@@ -92,7 +92,7 @@ static bool IsLowerSnakeCase(const std::string &str) {
   return true;
 }
 
-// Convert an underscore_based_indentifier in to camelCase.
+// Convert an underscore_based_identifier in to camelCase.
 // Also uppercases the first character if first is true.
 std::string MakeCamel(const std::string &in, bool first) {
   std::string s;