feat(docs): adding CLA information to CONTRIBUTING.md

Author: alexander-akait

.github/CONTRIBUTING.md

@@ -147,6 +147,14 @@ module. Thankfully, Github provides a means to do this. Add a dependency to the
 
 Where `{id}` is the # ID of your Pull Request.
 
+## Contributor License Agreement
+
+When submitting your contribution, a CLA (Contributor License Agreement) bot will come by to verify that you signed the [CLA](https://cla.js.foundation/webpack-contrib/webpack-defaults).
+If it is your first time, it will link you to the right place to sign it.
+However, if you have committed your contributions using an email that is not the same as your email used on GitHub, the CLA bot can't accept your contribution.
+
+Run `git config user.email` to see your Git email, and verify it with [your GitHub email](https://github.com/settings/emails).
+
 ## Thanks
 
 For your interest, time, understanding, and for following this simple guide.

templates/.github/CONTRIBUTING.md

@@ -147,6 +147,14 @@ module. Thankfully, Github provides a means to do this. Add a dependency to the
 
 Where `{id}` is the # ID of your Pull Request.
 
+## Contributor License Agreement
+
+When submitting your contribution, a CLA (Contributor License Agreement) bot will come by to verify that you signed the [CLA](https://cla.js.foundation/${repo}).
+If it is your first time, it will link you to the right place to sign it.
+However, if you have committed your contributions using an email that is not the same as your email used on GitHub, the CLA bot can't accept your contribution.
+
+Run `git config user.email` to see your Git email, and verify it with [your GitHub email](https://github.com/settings/emails).
+
 ## Thanks
 
 For your interest, time, understanding, and for following this simple guide.