Add SSH fix (slow connection)

README.md

@@ -438,6 +438,8 @@ For example, you can connect to a device with the IP 192.168.2.51 on the WiFi ne
 ssh -J pi@raspberrypi.local 192.168.2.51
 ```
 
+It is possible to encounter an issue where SSH is very slow... One possible fix is to disable reverse DNS lookup using [this fix](https://linux-tips.com/t/disabling-reverse-dns-lookups-in-ssh/222). Just uncomment `UseDNS no` in `/etc/ssh/sshd_config`.
+
 ## Install PlatformIO
 
 PlatformIO will be necessary if we want to flash program to microcontrollers connected to the Raspberry Pi.