Add explanation for inner attribute

Author: bishtpawan

src/librustc_error_codes/error_codes/E0710.md

@@ -1,13 +1,27 @@
 An unknown tool name found in scoped lint
 
-Erroneous code example:
+Erroneous code examples:
 
 ```compile_fail,E0710
 #[allow(clipp::filter_map)] // error!`
 fn main() {
-    /**
-    *business logic
-    */
+    // business logic
+}
+```
+
+```compile_fail,E0710
+#[warn(clipp::filter_map)] // error!`
+fn main() {
+    // business logic
+}
+```
+
+```compile_fail,E0710
+fn main() {
+    #![deny(clipp::filter_map)] //error!
+    fn filter() {
+        //logic
+    }
 }
 ```
 
@@ -17,8 +31,22 @@ forget to import it in you project:
 ```
 #[allow(clippy::filter_map)] // ok!
 fn main() {
-    /**
-    *business logic
-    */
+    // business logic
+}
+```
+
+```
+#[warn(clippy::filter_map)] // ok!
+fn main() {
+    // business logic
+}
+```
+
+```
+fn main() {
+    #![deny(clippy::filter_map)] // ok!
+    fn filter() {
+        //logic
+    }
 }
 ```