Add the Ansible community 13.0.0a3 porting guide (#3139)

Co-authored-by: Felix Fontein <5781356+felixfontein@users.noreply.github.com>

docs/docsite/rst/porting_guides/porting_guide_13.rst

@@ -15,6 +15,43 @@ Ansible 13 is based on Ansible-core 2.20.
 
 We suggest you read this page along with the `Ansible 13 Changelog <https://github.com/ansible-community/ansible-build-data/blob/main/13/CHANGELOG-v13.md>`_ to understand what updates you may need to make.
 
+Porting Guide for v13.0.0a3
+===========================
+
+Major Changes
+-------------
+
+grafana.grafana
+^^^^^^^^^^^^^^^
+
+- Fallback to empty dict in case grafana_ini is undefined by @root-expert in https://github.com/grafana/grafana-ansible-collection/pull/403
+- Fix Mimir config file validation task by @Windos in https://github.com/grafana/grafana-ansible-collection/pull/428
+- Fixes issue by @digiserg in https://github.com/grafana/grafana-ansible-collection/pull/421
+- Import custom dashboards only when directory exists by @mahendrapaipuri in https://github.com/grafana/grafana-ansible-collection/pull/430
+- Updated YUM repo urls from `packages.grafana.com` to `rpm.grafana.com` by @DejfCold in https://github.com/grafana/grafana-ansible-collection/pull/414
+- Use credentials from grafana_ini when importing dashboards by @root-expert in https://github.com/grafana/grafana-ansible-collection/pull/402
+- do not skip scrape latest github version even in check_mode by @cmehat in https://github.com/grafana/grafana-ansible-collection/pull/408
+- fix datasource documentation by @jeremad in https://github.com/grafana/grafana-ansible-collection/pull/437
+- fix mimir_download_url_deb & mimir_download_url_rpm by @germebl in https://github.com/grafana/grafana-ansible-collection/pull/400
+- update catalog info by @Duologic in https://github.com/grafana/grafana-ansible-collection/pull/434
+- use deb822 for newer debian versions by @Lukas-Heindl in https://github.com/grafana/grafana-ansible-collection/pull/440
+
+Deprecated Features
+-------------------
+
+community.hrobot
+^^^^^^^^^^^^^^^^
+
+- storagebox\* modules - membership in the ``community.hrobot.robot`` action group (module defaults group) is deprecated; the modules will be removed from the group in community.hrobot 3.0.0. Use ``community.hrobot.api`` instead (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox\* modules - the ``hetzner_token`` option for these modules will be required from community.hrobot 3.0.0 on (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox\* modules - the ``hetzner_user`` and ``hetzner_pass`` options for these modules are deprecated; support will be removed in community.hrobot 3.0.0. Use ``hetzner_token`` instead (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox_info - the ``storageboxes[].login``, ``storageboxes[].disk_quota``, ``storageboxes[].disk_usage``, ``storageboxes[].disk_usage_data``, ``storageboxes[].disk_usage_snapshot``, ``storageboxes[].webdav``, ``storageboxes[].samba``, ``storageboxes[].ssh``, ``storageboxes[].external_reachability``, and ``storageboxes[].zfs`` return values are deprecated and will be removed from community.routeros. Check out the documentation to find out their new names according to the new API (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox_snapshot_info - the ``snapshots[].timestamp``, ``snapshots[].size``, ``snapshots[].filesystem_size``, ``snapshots[].automatic``, and ``snapshots[].comment`` return values are deprecated and will be removed from community.routeros. Check out the documentation to find out their new names according to the new API (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox_snapshot_plan - the ``plans[].month`` return value is deprecated, since it only returns ``null`` with the new API and cannot be set to any other value (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox_snapshot_plan_info - the ``plans[].month`` return value is deprecated, since it only returns ``null`` with the new API and cannot be set to any other value (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox_subaccount - the ``subaccount.homedirectory``, ``subaccount.samba``, ``subaccount.ssh``, ``subaccount.external_reachability``, ``subaccount.webdav``, ``subaccount.readonly``, ``subaccount.createtime``, and ``subaccount.comment`` return values are deprecated and will be removed from community.routeros. Check out the documentation to find out their new names according to the new API (https://github.com/ansible-collections/community.hrobot/pull/178).
+- storagebox_subaccount_info - the ``subaccounts[].accountid``, ``subaccounts[].homedirectory``, ``subaccounts[].samba``, ``subaccounts[].ssh``, ``subaccounts[].external_reachability``, ``subaccounts[].webdav``, ``subaccounts[].readonly``, ``subaccounts[].createtime``, and ``subaccounts[].comment`` return values are deprecated and will be removed from community.routeros. Check out the documentation to find out their new names according to the new API (https://github.com/ansible-collections/community.hrobot/pull/178).
+
 Porting Guide for v13.0.0a2
 ===========================