Not later than February 15 of the first year of each biennial legislative session, the governor shall transmit to the legislature a document to be known as the trailer bill containing any changes to statutory law deemed necessary for the ensuing biennium. This document shall be separate from the document known as the budget as provided in N.H. Rev. Stat. § 9:2 and shall not be considered a budget bill as provided in part II, article 18-a of the New Hampshire constitution. This document shall be available in printed format and at least one electronic computer file format in common use at the time and shall be publicly posted on the department of administrative services’ website on the date of the transmittal.