chore: fix typos

https://results.pre-commit.ci/run/github/760058710/1747600769.DyFj2_uuQvGFXmK1NhtAaA

Author: dangotbanned

narwhals/_plan/__init__.py

@@ -1,4 +1,4 @@
-"""Brainstorming an `Expr` internal represention.
+"""Brainstorming an `Expr` internal representation.
 
 Notes:
 - Each `Expr` method should be representable by a single node

narwhals/_plan/expr.py

@@ -226,7 +226,7 @@ def __repr__(self) -> str:
 
 
 class WindowExpr(ExprIR):
-    """A fully specified `.over()`, that occured after another expression.
+    """A fully specified `.over()`, that occurred after another expression.
 
     I think we want variants for partitioned, ordered, both.
 
@@ -310,7 +310,7 @@ def __repr__(self) -> str:
 class IndexColumns(ExprIR):
     """Renamed from `IndexColumn`.
 
-    `Nth` provides the singlular variant.
+    `Nth` provides the singular variant.
 
     https://github.com/pola-rs/polars/blob/112cab39380d8bdb82c6b76b31aca9b58c98fd93/crates/polars-plan/src/dsl/expr.rs#L80
     """

narwhals/_plan/options.py

@@ -180,7 +180,7 @@ class RollingOptionsFixedWindow(Immutable):
 
     window_size: int
     min_samples: int
-    """Renamed from `min_periods`, re-uses `window_size` if null."""
+    """Renamed from `min_periods`, reuses `window_size` if null."""
 
     center: bool
     fn_params: RollingVarParams | None