doc: format and ran prettier on precommit.md

Change-Id: Ibcff373bc817f2b67abbb45b85ae7ccb34b5bcfd
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/768318
CI-Result: Cloud Build <devtools-proctor-result-processor@system.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

doc/precommit.md

@@ -1,22 +1,24 @@
 ### Install pre-commit hook
 
 The `all.bash` script runs quickly enough so that you can use it as a git
-pre-commit hook. If you don't already have a pre-commit hook, you can install it with
+pre-commit hook. If you don't already have a pre-commit hook, you can install
+it with
 
 ```
 ln -s -f ../../all.bash .git/hooks/pre-commit
 ```
 
-Google workstations start with a small shell script as a pre-commit hook. To add
-`all.bash` to it, edit `.git/hooks/pre-commit` and add the line
+Google workstations start with a small shell script as a pre-commit hook. To
+add `all.bash` to it, edit `.git/hooks/pre-commit` and add the line
 
 ```
 ./all.bash
 ```
 
 You may prefer to run `all.bash` only when you push (which happens when you run
-`git codereview mail`). You'll need a small script to discard the arguments that
-the pre-push hook is called with. Make this the contents of `.git/hooks/pre-push`:
+`git codereview mail`). You'll need a small script to discard the arguments
+that the pre-push hook is called with. Make this the contents of
+`.git/hooks/pre-push`:
 
 ```
 #!/bin/sh
@@ -31,14 +33,14 @@ chmod +x .git/hooks/pre-push
 
 ### Running Linters/Formatters/Tests
 
-The `all.bash` script can be used to selectively run actions on the source (e.g.
-linters, code formatters, or tests). Run `./all.bash help` to see a list of
-supported actions.
+The `all.bash` script can be used to selectively run actions on the source
+(e.g. linters, code formatters, or tests). Run `./all.bash help` to see a list
+of supported actions.
 
 Some actions are not run by the default invocation of `./all.bash` that is
-executed in the commit hook. Notably, the `prettier` command is not run, because
-it has a dependency on nodejs, which is otherwise not needed and which not all
-developers have installed on their system.
+executed in the commit hook. Notably, the `prettier` command is not run,
+because it has a dependency on nodejs, which is otherwise not needed and which
+not all developers have installed on their system.
 
 If you are modifying CSS or Javascript, install prettier as described at
 https://prettier.io/docs/en/install.html, and run `./all.bash prettier` to