docs(readme): document --hook cli option

examples of how to incorporate commitizen into traditional git hooks + husky hooks

README.md

@@ -141,6 +141,38 @@ This will be more convenient for your users because then if they want to do a co
 
 > **NOTE:** if you are using `precommit` hooks thanks to something like `husky`, you will need to name your script some thing other than "commit" (e.g. "cm": "git-cz"). The reason is because npm-scripts has a "feature" where it automatically runs scripts with the name *prexxx* where *xxx* is the name of another script. In essence, npm and husky will run "precommit" scripts twice if you name the script "commit," and the work around is to prevent the npm-triggered *precommit* script.
 
+#### Optional: Running Commitizen on `git commit`
+
+This example shows how to incorporate Commitizen into the existing `git commit` workflow by using git hooks and the `--hook` command-line option. This is useful for project maintainers
+who wish to ensure the proper commit format is enforced on contributions from those unfamiliar with Commitizen.
+
+Once either of these methods is implemented, users running `git commit` will be presented with an interactive Commitizen session that helps them write useful commit messages. 
+
+> **NOTE:** This example assumes that the project has been set up to [use Commitizen locally](https://github.com/commitizen/cz-cli#optional-install-and-run-commitizen-locally).
+
+##### Traditional git hooks
+
+Update `.git/hooks/prepare-commit-msg` with the following code:
+
+```
+#!/bin/bash
+exec < /dev/tty
+node_modules/.bin/git-cz --hook
+```
+
+##### Husky 
+For `husky` users, add the following configuration to the project's `package.json`:
+
+```
+"husky": {
+  "hooks": {
+    "prepare-commit-msg": "exec < /dev/tty && git cz --hook",
+  }
+}
+```
+
+> **Why `exec < /dev/tty`?** By default, git hooks are not interactive. This command allows the user to use their terminal to interact with Commitizen during the hook.
+
 #### Congratulations your repo is Commitizen-friendly. Time to flaunt it!
 
 Add the Commitizen-friendly badge to your README using the following markdown: