Fixup comments

crates/mbe/src/to_parser_input.rs

@@ -47,6 +47,9 @@ pub(crate) fn to_parser_input(buffer: &TokenBuffer<'_>) -> parser::Input {
                         res.push(kind);
 
                         if kind == FLOAT_NUMBER && !inner_text.ends_with('.') {
+                            // Tag the token as joint if it is float with a fractional part
+                            // we use this jointness to inform the parser about what token split
+                            // event to emit when we encounter a float literal in a field access
                             res.was_joint();
                         }
                     }