Add instuctions for updating cloudflared binary.

docs/guides/dns-over-https.md

@@ -60,10 +60,12 @@ sudo useradd -s /usr/sbin/nologin -r -M cloudflared
 Proceed to create a configuration file for `cloudflared` by copying the following in to `/etc/default/cloudflared`. This file contains the command-line options that get passed to cloudflared on startup:
 
 ```bash
-# Commandline args for cloudflared
+# Commandline args for cloudflared, using Cloudflare DNS
 CLOUDFLARED_OPTS=--port 5053 --upstream https://1.1.1.1/dns-query --upstream https://1.0.0.1/dns-query
 ```
 
+**Note:** The `cloudflared` binary will work with other DoH providers (for example, you could use https://8.8.8.8/dns-query for Google DNS).
+
 Update the permissions for the configuration file and `cloudflared` binary to allow access for the cloudflared user:
 
 ```bash
@@ -223,3 +225,23 @@ sudo systemctl daemon-reload
 After the above, don't forget to change the DNS back to something else in Pi-hole's DNS settings!
 
 [^guide]: Based on [this guide by Ben Dews | bendews.com](https://bendews.com/posts/implement-dns-over-https/)
+
+### Updating Cloudflared
+
+The `cloudflared` tool will not receive updates through the package manager, however it can be updated
+manually by running these commands:
+
+```bash
+sudo cloudflared update
+sudo systemctl restart cloudflared
+```
+
+If you want to have the system update `cloudflared` automatically, simply place the update commands in the
+file `/etc/cron.weekly/cloudflared-updater.sh`, and adjust permissions:
+
+```bash
+sudo chmod +x /etc/cron.weekly/cloudflared-updater.sh
+sudo chown root:root /etc/cron.weekly/cloudflared-updater.sh
+```
+
+The system will now attempt to update the cloudflared binary automatically, once per week.