Storybook plugin deprecated

[daniele-zurico]

deprecating @storybook/addon-knobs in favor of @storybook/addon-controls

Documentation: https://www.npmjs.com/package/@storybook/addon-knobs

Please follow these instructions:

git checkout release/0.7
git pull
git checkout -b 'feature/storybook-deprecated-plugin'

create a PR with base branch release/0.7

[Jaya-Rathore]

1. As @storybook/addon-knobs has already been replaced in the code and no warnings encountered related to this plugin, no changes required.
2. Deprecating @storybook/addon-docs/blocks in favor of @storybook/addon-docs to resolve the warning while running storybook.
   Documentation : https://github.com/storybookjs/storybook/blob/next/MIGRATION.md#deprecated-scoped-blocks-imports

[daniele-zurico]

closed by #426