Remove redundant formatting script

We can invoke rustfmt directly via Bazel. It is not necessary to
explicitly mention these checks in the pull request template since
they're already hooked into the test command.

.github/pull_request_template.md

@@ -1,6 +1,7 @@
 # Description
 
-Please include a summary of the changes and the related issue. Please also include relevant motivation and context. 
+Please include a summary of the changes and the related issue. Please also
+include relevant motivation and context.
 
 Fixes # (issue)
 
@@ -10,18 +11,17 @@ Please delete options that are not relevant.
 
 - [ ] Bug fix (non-breaking change which fixes an issue)
 - [ ] New feature (non-breaking change which adds functionality)
-- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
+- [ ] Breaking change (fix or feature that would cause existing functionality to
+  not work as expected)
 - [ ] This change requires a documentation update
 
-# How Has This Been Tested?
+## How Has This Been Tested?
 
- Please also list any relevant details for your test configuration
+Please also list any relevant details for your test configuration
 
-# Checklist:
+## Checklist
 
-- [ ] I have run `bazel build @rules_rust//:rustfmt && ./rust_fmt.sh` to format my code
 - [ ] Updated documentation if needed
 - [ ] Tests added/amended
 - [ ] `bazel test //...`  passes locally
 - [ ] PR is contained in a single commit, using `git amend` see some [docs](https://www.atlassian.com/git/tutorials/rewriting-history)
-

CONTRIBUTING.md

@@ -1,8 +1,7 @@
 # Contributing to Turbo Cache
 
-Turbo Cache welcomes contribution from everyone. Here are the guidelines if you are
-thinking of helping us:
-
+Turbo Cache welcomes contribution from everyone. Here are the guidelines if you
+are thinking of helping us:
 
 ## Contributions
 
@@ -23,19 +22,28 @@ efforts from contributors on the same issue.
   main you may be asked to rebase your changes.
 
 - Commits should be as small as possible, while ensuring that each commit is
-  correct independently (i.e., each commit should compile and pass tests). 
+  correct independently (i.e., each commit should compile and pass tests).
 
-- Commits should be accompanied by a Developer Certificate of Origin
-  (http://developercertificate.org) sign-off, which indicates that you (and
-  your employer if applicable) agree to be bound by the terms of the
-  [project license](LICENSE). In git, this is the `-s` option to `git commit`.
+- Commits should be accompanied by a [Developer Certificate of Origin](http://developercertificate.org)
+  sign-off, which indicates that you (and your employer if applicable) agree to
+  be bound by the terms of the [project license](LICENSE). In git, this is the
+  `-s` option to `git commit`.
 
 - If your patch is not getting reviewed or you need a specific person to review
   it, you can @-reply a reviewer asking for a review in the pull request or a
   comment.
 
 - Add tests relevant to the fixed bug or new feature.
 
+- If `rustfmt` complains you can use the following command to apply its
+  suggested changes to the Rust sources:
+
+  ```bash
+  bazel run \
+    --@rules_rust//:rustfmt.toml=//:.rustfmt.toml \
+    @rules_rust//:rustfmt
+  ```
+
 ## Conduct
 
 Turbo Cache Code of Conduct is available in the