Add link to the feature freeze tracking issue to the book

Author: flip1995

.github/workflows/feature-freeze.yml renamed to .github/workflows/feature_freeze.yml

@@ -22,4 +22,4 @@ jobs:
         COMMENT="**Seems that you are trying to add a new lint!**\nWe are currently in a [feature freeze](https://doc.rust-lang.org/nightly/clippy/development/feature_freeze.html), so we are delaying all lint-adding PRs to August 1st and focusing on bugfixes.\nThanks a lot for your contribution, and sorry for the inconvenience.\nWith ❤ from the Clippy team"
         GITHUB_TOKEN=${{ secrets.GITHUB_TOKEN }}
         COMMENT_URL="https://api.github.com/repos/${{ github.repository }}/issues/${PR_NUMBER}/comments"
-        curl -s -H "Authorization: token ${GITHUB_TOKEN}" -X POST $COMMENT_URL -d "{\"body\":\"$COMMENT\"}"
+        curl -s -H "Authorization: token ${GITHUB_TOKEN}" -X POST $COMMENT_URL -d "{\"body\":\"$COMMENT\"}"

book/src/development/feature_freeze.md

@@ -26,6 +26,9 @@ adding additional load into our reviewing schedules.
 Thanks a lot to everyone who wants to help Clippy become better software in this feature freeze period!
 If you'd like to help, making a bugfix, making sure that it works, and opening a PR is a great step!
 
+To find things to fix, go to the [tracking issue][tracking_issue], find an issue that you like, go there and claim that
+issue with `@rustbot claim`.
+
 As a general metric and always taking into account your skill and knowledge level, you can use this guide:
 
 - 🟥 [ICEs][search_ice], these are compiler errors that causes Clippy to panic and crash. Usually involves high-level
@@ -49,3 +52,4 @@ trench coat.
 [sugg_causes_bug]: https://github.com/rust-lang/rust-clippy/issues?q=sort%3Aupdated-desc%20state%3Aopen%20label%3AI-suggestion-causes-bug
 [sugg_causes_error]: https://github.com/rust-lang/rust-clippy/issues?q=sort%3Aupdated-desc%20state%3Aopen%20label%3AI-suggestion-causes-error%20
 [false_positive]: https://github.com/rust-lang/rust-clippy/issues?q=sort%3Aupdated-desc%20state%3Aopen%20label%3AI-false-positive
+[tracking_issue]: https://github.com/rust-lang/rust-clippy/issues/15086