docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/nextcloud/nextcloud.conf.j2

@@ -0,0 +1,22 @@
+Listen {{ nextcloud_web_port }}
+
+<VirtualHost *:{{ nextcloud_web_port }}>
+  ServerAdmin webmaster@{{ nextcloud_domain }}
+  ServerName {{ nextcloud_domain }}
+  ServerAlias rosalind.incus
+  
+  DocumentRoot /var/www/nextcloud
+
+  <Directory /var/www/nextcloud/>
+    Require all granted
+    AllowOverride All
+    Options FollowSymLinks MultiViews
+
+    <IfModule mod_dav.c>
+      Dav off
+    </IfModule>
+  </Directory>
+
+  ErrorLog ${APACHE_LOG_DIR}/nextcloud_error.log
+  CustomLog ${APACHE_LOG_DIR}/nextcloud_access.log combined
+</VirtualHost>