porting_guide_2.8 - fix broken links (#55092)

* porting_guide_2.8 - fix broken links in deprecated modules section

docs/docsite/rst/porting_guides/porting_guide_2.8.rst

@@ -233,12 +233,12 @@ Deprecation notices
 
 The following modules will be removed in Ansible 2.12. Please update your playbooks accordingly.
 
-* ``foreman`` use <https://github.com/theforeman/foreman-ansible-modules> instead.
-* ``katello`` use <https://github.com/theforeman/foreman-ansible-modules> instead.
+* ``foreman`` use `foreman-ansible-modules <https://github.com/theforeman/foreman-ansible-modules>`_ instead.
+* ``katello`` use `foreman-ansible-modules <https://github.com/theforeman/foreman-ansible-modules>`_ instead.
 * ``github_hooks`` use :ref:`github_webhook <github_webhook_module>` and :ref:`github_webhook_facts <github_webhook_facts_module>` instead.
-* ``digital_ocean`` use :ref `digital_ocean_droplet <digital_ocean_droplet_module>` instead.
-* ``gce`` use :ref `gce_compute_instance <gce_compute_instance_module>` instead.
-* ``panos`` use `Ansible Galaxy role <https://galaxy.ansible.com/PaloAltoNetworks/paloaltonetworks>`_ instead.
+* ``digital_ocean`` use :ref:`digital_ocean_droplet <digital_ocean_droplet_module>` instead.
+* ``gce`` use :ref:`gcp_compute_instance <gcp_compute_instance_module>` instead.
+* ``panos`` use the `Palo Alto Networks Ansible Galaxy role <https://galaxy.ansible.com/PaloAltoNetworks/paloaltonetworks>`_ instead.
 
 
 Noteworthy module changes