Mailly-le-Château is too small to have a literature of its own, but the wider Burgundy and Yonne valley have inspired excellent writing.
The Stones of the Abbey by Fernand Pouillon (1964, trans. Edward Gillott) — A novel set in the construction of a Cistercian abbey in medieval Burgundy. Pouillon was an architect, and his account of how medieval builders worked — the logistics, the materials, the physical effort — is the best fictional introduction to the Romanesque stonework you will see throughout this region.
My Lark by Jean-Louis Barrault — The great actor and director grew up in Burgundy and wrote vividly about the particular quality of light and silence in the Yonne countryside. Out of print but findable; worth the effort.
A Year in Burgundy (various documentary accounts) — Several memoirs of the year-in-Burgundy genre exist, most focused on wine country to the south (Beaune, Meursault). They capture the rhythm of Burgundian village life — the market, the harvest, the long lunches — that you will recognise in Mailly-le-Château even if the terroir is different.
Travels with a Donkey in the Cévennes by Robert Louis Stevenson — Strictly speaking this is the wrong region, but Stevenson's account of slow travel through rural France on a barge and later on foot is the closest literary precursor to the canal journey through Burgundy. The pleasures he describes — silence, a good halt, the kindness of rural innkeepers — translate directly.
The Canal by Henri Vincenot — Vincenot was a Burgundian writer who wrote lovingly about the culture of the canal-boat workers (mariniers) who worked the Nivernais and the Yonne. His fiction captures a way of life that survived into living memory and that you can still glimpse in the older boats moored below the cliff.