Revert "Delete .venv directory"

This reverts commit 5a2693bd9f.

.venv/lib/python3.9/site-packages/matplotlib/mpl-data/stylelib/fast.mplstyle

@@ -0,0 +1,11 @@
+# a small set of changes that will make your plotting FAST (1).
+#
+# (1) in some cases
+
+# Maximally simplify lines.
+path.simplify: True
+path.simplify_threshold: 1.0
+
+# chunk up large lines into smaller lines!
+# simple trick to avoid those pesky O(>n) algorithms!
+agg.path.chunksize: 10000