Added missing strings to erp.php

[DAnn2012]

Changes proposed in this Pull Request:

Update erp.php

[DAnn2012]

Hi @RatulHasan ,

please could you kindly take a look at my PR?

Thank you.

[DAnn2012]

What are the following three lines about?

wp-erp/i18n/languages/erp.php

Lines 18 to 20 in 03b800f

	_x( 'ltr', 'text direction' ),
	_n( ' + valueExpression + ' ),
	_e( ' + (JSON.stringify(comment.text)) + ' ),

[RatulHasan]

This is an auto-generated php file. No need to add translatable text in this file.