Add deployment template schema for Edge Runtime 1.1 and 1.2

[marianan]

This change adds deployment template manifest schema to support EdgeRuntime 1.1 and 1.2 updated schemas.
The schema resolves without issues locally but fails when added to tests in the repo - I am still investigating this but wanted to get started on the review of the changes in parallel.

[GerryFerdinandus]

@marianan
You must also update the schema-validation.json if you $ref one schema to the other.
Look at the other example.

schemastore/src/schema-validation.json

Lines 137 to 154 in aa6a982

	{
	"azure-iot-edge-deployment-template-1.0.json": {
	"externalSchema": [
	"azure-iot-edge-deployment-1.0.json"
	]
	}
	},
	{
	"azure-iot-edge-deployment-template-2.0.json": {
	"unknownKeywords": [
	"examples",
	"contentMediaType"
	],
	"externalSchema": [
	"azure-iot-edge-deployment-2.0.json"
	]
	}
	},

[marianan]

thanks for the example. i updated the schema-validation.json

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In reply to: 894432333

[GerryFerdinandus]

@madskristensen Don't forget to merge this PR from last week

[madskristensen]

Thanks