Apply formatting to new lessons

Author: huangsam

ultimatepython/advanced/subinterpreters.py

@@ -6,6 +6,7 @@
 has its own Global Interpreter Lock (GIL), enabling true multi-core
 parallelism for Python code.
 """
+
 import concurrent.futures
 import concurrent.interpreters as interpreters
 

ultimatepython/syntax/template_strings.py

@@ -6,6 +6,7 @@
 the string.templatelib module. This allows for deferred evaluation and
 custom processing of the template parts and interpolations.
 """
+
 import string.templatelib