Docs: style: multiline brackets (#3143)

docs/style.md

@@ -17,6 +17,15 @@
 * Use type annotations where possible for function signatures and class members.
 * Use type annotations where appropriate for local variables (e.g. `var: List[int] = []`, or when the
   type is hard or impossible to deduce.) Clear annotations help developers look up and validate API calls.
+* If a line ends with an open bracket/brace/parentheses, the matching closing bracket should be at the
+  beginning of a line at the same indentation as the beginning of the line with the open bracket.
+  ```python
+  stuff = {
+      x: y
+      for x, y in thing
+      if y > 2
+  }
+  ```
 * New classes, attributes, and methods in core code should have docstrings that follow
   [reST style](https://peps.python.org/pep-0287/).
 * Worlds that do not follow PEP8 should still have a consistent style across its files to make reading easier.