fix: Expand on why not :: but separate tables

Author: epage

text/3389-manifest-lint.md

@@ -205,9 +205,13 @@ and other fields that are more workspace related.  Instead, we used
 
 Instead of `<tool>.<lint>`, we could use `<tool>::<lint>` (e.g.
 `"clipp::enum_glob_use"` instead of `clippy.enum_glob_use`), like in the
-diagnostic messages.  This would make it easier to copy/paste lint names but it
-will requiring quoting the keys and is more difficult to add tool-level
-configuration in the future.
+diagnostic messages.  This would make it easier to copy/paste lint names.
+However, with the schema being `<lint> = <level>`, this would require quoting
+the keys rather than leaving them as bare words.  This would also cause
+problems for tool-level configuration.  The first is that the lints wouldn't be
+easily grouped with their config.  The second is if we use `<lint> = <level>`,
+we'd be mixing tool names in with lints, making it easier to conflict and
+harder to collect all lints to forward to a tool.
 
 We could possibly extend this new field to `rustfmt` by shifting the focus from
 "lints" to "rules" (see