Add note about lint level attributes to pre-expansion lints

Author: xFrednet

clippy_lints/src/dbg_macro.rs

@@ -15,6 +15,13 @@ declare_clippy_lint! {
     /// `dbg!` macro is intended as a debugging tool. It
     /// should not be in version control.
     ///
+    /// ### Known problems!
+    /// * The lint level can't be changed by attributes, like most other lints.
+    ///   To change the lint level, please use command line flags instead.
+    ///   More information and a configuration example can be found in [clippy#6610].
+    ///
+    /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
+    ///
     /// ### Example
     /// ```rust,ignore
     /// // Bad

clippy_lints/src/write.rs

@@ -72,7 +72,12 @@ declare_clippy_lint! {
     /// application and might forget to remove those prints afterward.
     ///
     /// ### Known problems
-    /// Only catches `print!` and `println!` calls.
+    /// * Only catches `print!` and `println!` calls.
+    /// * The lint level can't be changed by attributes, like most other lints.
+    ///   To change the lint level, please use command line flags instead.
+    ///   More information and a configuration example can be found in [clippy#6610].
+    ///
+    /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
     ///
     /// ### Example
     /// ```rust
@@ -94,7 +99,12 @@ declare_clippy_lint! {
     /// application and might forget to remove those prints afterward.
     ///
     /// ### Known problems
-    /// Only catches `eprint!` and `eprintln!` calls.
+    /// * Only catches `eprint!` and `eprintln!` calls.
+    /// * The lint level can't be changed by attributes, like most other lints.
+    ///   To change the lint level, please use command line flags instead.
+    ///   More information and a configuration example can be found in [clippy#6610].
+    ///
+    /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
     ///
     /// ### Example
     /// ```rust