Installing the Schematics CLI
The Schematics CLI is a command-line interface that we can use to interact with the Schematics API. To install it, run the following npm command:
npm install -g @angular-devkit/schematics-cli
    The preceding command will install the @angular-devkit/schematics-cli npm package globally on our system. We can then use the schematics executable to create a new collection for the schematics:
schematics blank my-schematics
    The previous command will generate a schematics project called my-schematics. It contains a schematic with the same name by default inside the src folder. A schematic includes the following files:
collection.json: A JSON schema that describes the schematics that belong to themy-schematicscollection.my-schematics\index.ts: The main entry point of the schematic.my-schematics\index_spec.ts: The unit test file of the main entry point of the schematic.
The JSON schema file of the collection contains...