Warning for swaps greater that 16,777,215 Sats

It seems that there is a hard limit built into lightning at 16,777,215 sats.

I didn't know that when joining a swap.  As a lot of people are now just getting started, it may be important to make a flashing notice to inform people of this issue when opening swaps greater that that hard limit. 

I have found documentation on how to get around this issue, but again some are still newer and it says if we make this change it could impact automatic updates.

https://community.getumbrel.com/t/lightning-max-channel-size-is-0-16777215-btc/2524/2