Implemented usage of custom package name in the generated package

[przemyslaw-zan]

Suggested merge commit message (convention)

Feature: The provided package name will now be used as a default name of a plugin (instead of MyPlugin) in the generated package. Closes #54.

Feature: Added the --plugin-name option that allows specifying the plugin name different from the package name. See #54.

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Additional information

For example – encountered issues, assumptions you had to make, other affected tickets, etc.

Supported scopes

• generator → https://www.npmjs.com/package/ckeditor5-package-generator
• * → https://www.npmjs.com/package/@ckeditor/ckeditor5-package-*

[pomek]

Something went wrong :(

node /Users/pomek/Projects/ckeditor/ckeditor5-package-generator/packages/ckeditor5-package-generator/bin/index.js @pomek/ckeditor5-example-package --dev --use-yarn --lang js
📍 Verifying the specified package name.
📍 Checking whether the "ckeditor5-example-package" directory can be created.
📍 Creating the directory "/Users/pomek/Projects/tmp/ckeditor5-example-package".
📍 Collecting the latest CKEditor 5 packages versions...
📍 Copying files...
📍 Installing dependencies... It takes a while.
📍 Initializing Git repository...
📍 Installing Git hooks...

Done!

Execute the "cd ckeditor5-example-package" command to change the current working directory
to the newly created package. Then, the package offers a few predefined scripts:

  * start - for creating the HTTP server with the editor sample,
  * test - for executing unit tests of an example plugin,
  * lint - for running a tool for static analyzing JavaScript files,
  * stylelint - for running a tool for static analyzing CSS files.

Example: yarn run start

 pomek@MBP-2020.local  ~/Projects/tmp  cd ckeditor5-example-package/
 pomek@MBP-2020.local  ~/.../tmp/ckeditor5-example-package   master (7a30f30)  yarn run start
yarn run v1.22.18
error Couldn't find a package.json file in "/Users/pomek/Projects/tmp/ckeditor5-example-package"
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[pomek]

I left a few comments.

Other than that, I guess the source files in the templates/ directory should no longer follow the .js and .ts extensions. I am fine with using *.txt, but we lose code highlighting. It does not work, though, as we have a lot of syntax errors right now.

[pomek]

LGTM.