use EW-72 dot config

docs/BUILD.md

@@ -198,6 +198,12 @@ TODO: Make `defconfig` for different hardware.
 
 Hit `<TAB>` to get to `EXIT`, then `<ENTER>` to select `Yes` to save the configuration.
 
+Or just exit `menuconfig` and use this instead:
+
+```
+wget -O .config https://spacecruft.org/network/maxwell/raw/branch/master/config/dot-config-ew-72
+```
+
 ## Build Source
 
 Now, actually build it. Takes over an hour or two, depending on hardware.