v2.9.0

What's changed

• feat(doc): Word 6.0/95 through the Word 97 story walker — tables, headings, bold, headers, footnotes (2413d90)
• perf(pdf): release the text layer's spare node capacity (185419a)
• perf(core): JSON export without deep copies of its items (19985a9)
• perf(pdf): convert the text layer a page at a time (dd4da43)
• fix(pdf): don't keep the per-glyph buffer behind a page's text cells (37213cb)

Full changelog: v2.8.0...v2.9.0