added note about ssh keys

Author: remi-kazeroni

_episodes/07-development-setup.md

@@ -70,8 +70,10 @@ git clone https://github.com/ESMValGroup/ESMValTool.git
 This command will ask your GitHub username and a personal **token** as password.
 Please follow instructions on
 [GitHub token authentication requirements][token-authentication-requirements]
-to create a personal access token. After the authentication,
-the output might look like:
+to create a personal access token.
+Alternatively, you could [generate a new SSH key][generate-ssh-key] and
+[add it to your GitHub account][add-ssh-key].
+After the authentication, the output might look like:
 
 ~~~
 Cloning into 'ESMValTool'...

_includes/links.md

@@ -1,5 +1,6 @@
 {% include base_path.html %}
 [activate-environment]: https://docs.esmvaltool.org/en/latest/quickstart/installation.html#pre-installed-versions-on-hpc-clusters-other-servers
+[add-ssh-key]: https://docs.github.com/en/authentication/connecting-to-github-with-ssh/adding-a-new-ssh-key-to-your-github-account
 [cc-by-human]: https://creativecommons.org/licenses/by/4.0/
 [cc-by-legal]: https://creativecommons.org/licenses/by/4.0/legalcode
 [ci]: http://communityin.org/
@@ -17,6 +18,7 @@
 [diagnostic]: https://github.com/ESMValGroup/ESMValTool/blob/main/esmvaltool/diag_scripts/examples/diagnostic.py
 [ds]: https://github.com/ESMValGroup/ESMValTool_Tutorial/blob/main/data/dataset.urls
 [email]: mailto:[email protected]
+[generate-ssh-key]: https://docs.github.com/en/authentication/connecting-to-github-with-ssh/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent
 [github-importer]: https://import.github.com/
 [importer]: https://github.com/new/import
 [install-from-source]: https://docs.esmvaltool.org/en/latest/quickstart/installation.html#install-from-source