Fix sphinx/build_docs warnings for fractals

Author: MaximSmolskiy

fractals/julia_sets.py

@@ -13,7 +13,7 @@
 - Other examples from https://en.wikipedia.org/wiki/Julia_set
 - An exponential map Julia set, ambiantly homeomorphic to the examples in
 https://www.math.univ-toulouse.fr/~cheritat/GalII/galery.html
- and
+and
 https://ddd.uab.cat/pub/pubmat/02141493v43n1/02141493v43n1p27.pdf
 
 Remark: Some overflow runtime warnings are suppressed. This is because of the
@@ -67,7 +67,7 @@ def eval_quadratic_polynomial(c_parameter: complex, z_values: np.ndarray) -> np.
 def prepare_grid(window_size: float, nb_pixels: int) -> np.ndarray:
     """
     Create a grid of complex values of size nb_pixels*nb_pixels with real and
-     imaginary parts ranging from -window_size to window_size (inclusive).
+    imaginary parts ranging from -window_size to window_size (inclusive).
     Returns a numpy array.
 
     >>> prepare_grid(1,3)

fractals/koch_snowflake.py

@@ -6,10 +6,12 @@
     successive stage is formed by adding outward bends to each side of the
     previous stage, making smaller equilateral triangles.
     This can be achieved through the following steps for each line:
-        1. divide the line segment into three segments of equal length.
-        2. draw an equilateral triangle that has the middle segment from step 1
+
+    1. divide the line segment into three segments of equal length.
+    2. draw an equilateral triangle that has the middle segment from step 1
         as its base and points outward.
-        3. remove the line segment that is the base of the triangle from step 2.
+    3. remove the line segment that is the base of the triangle from step 2.
+
     (description adapted from https://en.wikipedia.org/wiki/Koch_snowflake )
     (for a more detailed explanation and an implementation in the
     Processing language, see  https://natureofcode.com/book/chapter-8-fractals/

fractals/sierpinski_triangle.py

@@ -4,14 +4,15 @@
 Simple example of fractal generation using recursion.
 
 What is the Sierpiński Triangle?
+
     The Sierpiński triangle (sometimes spelled Sierpinski), also called the
-Sierpiński gasket or Sierpiński sieve, is a fractal attractive fixed set with
-the overall shape of an equilateral triangle, subdivided recursively into
-smaller equilateral triangles. Originally constructed as a curve, this is one of
-the basic examples of self-similar sets—that is, it is a mathematically
-generated pattern that is reproducible at any magnification or reduction. It is
-named after the Polish mathematician Wacław Sierpiński, but appeared as a
-decorative pattern many centuries before the work of Sierpiński.
+    Sierpiński gasket or Sierpiński sieve, is a fractal attractive fixed set with
+    the overall shape of an equilateral triangle, subdivided recursively into
+    smaller equilateral triangles. Originally constructed as a curve, this is one of
+    the basic examples of self-similar sets—that is, it is a mathematically
+    generated pattern that is reproducible at any magnification or reduction. It is
+    named after the Polish mathematician Wacław Sierpiński, but appeared as a
+    decorative pattern many centuries before the work of Sierpiński.
 
 
 Usage: python sierpinski_triangle.py <int:depth_for_fractal>