Obsolete and delete --copy-from option of the create command

[vchimev]

According to CLI docs:

--copy-from - Specifies a directory which contains an existing NativeScript project.

PR: #2346 (Issue: #2301) changes the behavior of the --copy-from option.

Example:

tns create appTest --copy-from <app root dir>/app

Before:

The appTest/package.json will contain all dependencies described in <root>/app/package.json.

After:

The appTest/package.json will contain NO dependencies, as they are no longer described in <root>/app/package.json.

Consider to:

• obsolete the option with 2.5.0,
• delete the option with 2.6.0.