"no rule to make" on all platforms, except for skeleton

[Arthur Hebert]

Hello,

I am trying Nard for the first time, and having trouble with the basics, so
I assume I'm missing something rudimentary.

I ran `make skeleton` and it completed successfully.

My end-goal is to make a server running nodejs, so I've created the
following 2 files in a new platform folder:

$ cat platform/nodeserver/Rules.mk
PRODUCT_DEPS += skeleton
-include $(PATH_TOP)/platform/skeleton/Rules.mk
PKGS_APPS += debian/debian

$ cat platform/nodeserver/debian.config
deb_install += nodejs
deb_install += npm
deb_install += i2c-tools
deb_install += wget
deb_install += openssl

Then when I run `make nodeserver`, I get the message:
make: *** No rule to make target `nodeserver`. Stop.

Then I did `make clean` followed by `make mediaplayer` to try one of the
built-in alternatives and got the same message:
make: *** No rule to make target `mediaplayer`. Stop.

How do I build other products? Any help is much appreciated!

Thanks,
Arthur