Consitent spacing (#546)

requirements.txt

@@ -2,7 +2,7 @@ torch >= 2.3.0             # all
 jupyterlab >= 4.0          # all
 tiktoken >= 0.5.1          # ch02; ch04; ch05
 matplotlib >= 3.7.1        # ch04; ch06; ch07
-tensorflow>=2.18.0         # ch05; ch06; ch07
+tensorflow >= 2.18.0       # ch05; ch06; ch07
 tqdm >= 4.66.1             # ch05; ch07
 numpy >= 1.26, < 2.1       # dependency of several other libraries like torch and pandas
 pandas >= 2.2.1            # ch06