Unnecessary manifest_typings.json entry for embedded:network/* causes warning

[cmidgley]

Build environment: Windows (problem likely occurs on all)
Moddable SDK version: Latest released as of today (any within last six months)
Target device: Win, ESP32

Description
When compiling TypeScript and using examples/manifest_typings.json you get a warning on each build:

# warning: no modules match: c:\moddable\typings\embedded_network\*!

This is because six months ago a change was made that added:

"embedded:network/*": [
	"$(TYPINGS)/embedded_network/*"
]

However, no type files are located at that location (they are all in sub-directories and specifically included in the typings).

Removing this line from examples/manifest_typings.json continues to compile TypeScript but without the warning message.

Steps to Reproduce

1. Set up a TypeScript app that has a manifest.json that includes:

	"include": [
		"$(MODDABLE)/examples/manifest_typings.json",
	],

2. Compile with mcconfig
3. See warning in first line output

[cmidgley]

Fix proposed as part of #1429. Closing as it’s not a big deal and we can discuss if necessary there.