docs: basics.md: mention lintcheck

doc/basics.md

@@ -11,8 +11,9 @@ the codebase take a look at [Adding Lints] or [Common Tools].
   - [Get the Code](#get-the-code)
   - [Building and Testing](#building-and-testing)
   - [`cargo dev`](#cargo-dev)
-  - [Common Abbreviations](#common-abbreviations)
+  - [lintcheck](#lintcheck)
   - [PR](#pr)
+  - [Common Abbreviations](#common-abbreviations)
 
 ## Get the Code
 
@@ -91,6 +92,13 @@ cargo dev new_lint
 cargo dev ra_setup
 ```
 
+## lintcheck
+`cargo lintcheck` will build and run clippy on a fixed set of crates and generate a log of the results. You can `git diff` the updated log against its previous version and see what impact your lint made on a small set of crates.  
+If you add a new lint, please audit the resulting warnings and make sure there are no false positives and that the suggestions are valid.
+
+Refer to the tools [README] for more details.
+
+[README]: https://github.com/rust-lang/rust-clippy/blob/master/lintcheck/README.md
 ## PR
 
 We follow a rustc no merge-commit policy.