Release v0.7.4 — Long equations wrap instead of getting cut off

Bug fixes

• Wrap long display equations onto the next line in PDF export instead of cutting them off at the page edge (#146)
• Keep equation numbers from overlapping the formula, in the editor and in PDF export (#146)

UI/UX

• Wrap long equations in the editor instead of requiring horizontal scrolling, and remove stray scrollbars around formula blocks (#146)