docs: update docstrings for plate_row, plate_col, and name_pattern

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ieivanov

src/useq/_grid.py

@@ -61,6 +61,9 @@ class _GridPlan(_MultiPointPlan[PositionT]):
         Height of the field of view in microns. If not provided, acquisition engines
         should use current height of the FOV based on the current objective and camera.
         Engines MAY override this even if provided.
+    name_pattern : str
+        Format pattern for grid position names. Supported variables are
+        ``{row}``, ``{col}``, and ``{idx}``. By default, ``"{idx:04d}"``.
     """
 
     overlap: tuple[float, float] = Field(default=(0.0, 0.0), frozen=True)

src/useq/_position.py

@@ -40,9 +40,16 @@ class PositionBase(MutableModel):
     z : float | None
         Z position in microns.
     name : str | None
-        Optional name for the position.
+        Optional name for the position. If not provided but `plate_row` and
+        `plate_col` are set, a well name is auto-generated (e.g., "A1").
     sequence : MDASequence | None
         Optional MDASequence relative this position.
+    plate_row : int | None
+        Optional 0-based row index for well plate positions. Used to indicate
+        which well this position belongs to for HCS data storage.
+    plate_col : int | None
+        Optional 0-based column index for well plate positions. Used together
+        with `plate_row` to identify the well.
     row : int | None
         Optional row index, when used in a grid.
     col : int | None