Merge branch 'new_mirror_issue_template' into 'master'

Document how to add a new mirror

See merge request !283

.gitlab/issue_templates/New Mirror.md

+<!--
+This template should be used for adding a new Arch Linux Mirror on our own infrastructure.
+-->
+
+## Details
+
+- **Server name**: <!-- Put server hostname here -->
+
+## Steps
+
+1. [ ] Verify if the new mirror has enough diskspace for hosting a mirror.
+1. [ ] Add the new mirror in [archweb](https://archlinux.org/admin/mirrors/mirror/add) with these values:
+   - `Name`: <domain-name>
+   - `Tier`: `Tier 1`
+   - `Upstream`: `rsync.archlinux.org`
+   - `Public`: `checked`
+   - `Active`: `checked`
+   - `ISOs`: `checked`
+   - `Mirrors URLs`:
+      * `URL`: `https://<domain-name>/`
+      * `Country`: `Mirror country`
+      * `Bandwidth`: `Mirror bandwidth`
+   - `Mirrors Rsync IPs`: `Add the IPv4 and IPv6 address`
+1. [ ] Add a new domain in terraform
+1. [ ] Add the new server to `mirrors` in `hosts`
+1. [ ] Add a new `mirror_domain` key with <domain-name> as value
+1. [ ] Run the `gen_rsyncd` service on `rsync.archlinux.org` or wait till the systemd timer is triggered.
+1. [ ] Run the `mirrors.yml` playbook
+1. [ ] Run `certbot certonly --email webmaster@archlinux.org --agree-tos --rsa-key-size 4096 --renew-by-default --webroot -w /var/lib/letsencrypt/ -d <domain-name>`