"American Heritage Education in Minnesota Public Schools Act"; requiring school districts to develop and establish policies for grade level instruction to assure student access to founding documents of the country and the state pertinent to understanding the principles, character and world view of the founders; requiring school districts to permit principals or teachers to post the documents and prohibiting districts from limiting or restraining instruction in American or Minnesota state history or heritage based on religious references in documents, writings, speeches, proclamations or records, requiring use of the materials for educational purposes; authorizing students to voluntarily choose to read, write, share, report or otherwise study topics religious in nature under certain conditions (ra)