yapf: add page and Dutch translation (#5435)

pages/common/yapf.md

@@ -0,0 +1,16 @@
+# yapf
+
+> Python style guide checker.
+> More information: <https://github.com/google/yapf>.
+
+- Display a diff of the changes that would be made, without making them (dry-run):
+
+`yapf --diff {{path/to/file}}`
+
+- Format the file in-place and display a diff of the changes:
+
+`yapf --diff --in-place {{path/to/file}}`
+
+- Recursively format all Python files in a directory, concurrently:
+
+`yapf --recursive --in-place --style {{pep8}} --parallel {{path/to/directory}}`