fix: use require style import of yargs for --help

[forivall]

Description of change

Use import yargs = require("yargs") instead of import * to work around this issue

Without this change, i see the following behaviour:

» typeorm migration:generate --help
Options:
  --help     Show help                                                 [boolean]
  --version  Show version number

with this change, we get the full help

» typeorm migration:generate --help
typeorm migration:generate

Generates a new migration file with sql needs to be executed to update schema.

Options:
  -h, --help        Show help                                          [boolean]
  -c, --connection  Name of the connection on which run a query.
                                                            [default: "default"]
  -n, --name        Name of the migration class.             [string] [required]
  -d, --dir         Directory where migration should be created.
  -p, --pretty      Pretty-print generated SQL        [boolean] [default: false]
  -f, --config      Name of the file with connection configuration.
                                                          [default: "ormconfig"]
  -v, --version     Show version number                                [boolean]

Pull-Request Checklist

• Code is up-to-date with the master branch
• npm run lint passes with this change
• npm run test passes with this change
• This pull request links relevant issues as Fixes #0000 idk if there is an open issue. i searched but there are many open issues
• There are new or updated unit tests validating the change N/A
• Documentation has been updated to reflect this change N/A
• The new commits follow conventions explained in CONTRIBUTING.md

[imnotjames]

Just confirming - we can't use import yargs from "yargs"? I think this technique (import * as yargs) was when we were using a much older version of yargs and the newer one might differ & allow the default import?

[forivall]

import yargs from "yargs" may work -- i just made this change from the github web interface. Depending on the tsconfig, there's a chance it might not work. I'll make that tweak and checks it works later today or tomorrow.

[forivall]

@imnotjames sorry for the delay. import yargs from "yargs" works fine, and i've pushed the change.

[imnotjames]

Thanks for the contribution!