fixed typo

README.org

@@ -44,7 +44,7 @@ So far, notebooks are listed by difficulty, indicated by stars (☆ = simple,
   statistics and visualisation (☆☆)
 - [[file:notebooks/Dracor.ipynb][DraCor]] :: retrieving data from a REST API, text transformation and
   classification (☆☆)
-- [[file:notebooks/FCY.ipynb][FCA]] :: analysing characters in plays using Formal Concept Analysis
+- [[file:notebooks/FCA.ipynb][FCA]] :: analysing characters in plays using Formal Concept Analysis
   (☆☆)
 - [[file:notebooks/machine_learning.ipynb][Machine Learning]] :: recipes for common machine learning tasks (☆☆)
 - [[file:notebooks/Mondrian.ipynb][Mondrian]] :: turtle graphics, recursion, art (☆☆)