Clarify some comments

Author: camdecoster

src/plots/map/layout_defaults.js

@@ -39,14 +39,16 @@ function handleDefaults(containerIn, containerOut, coerce, opts) {
         handleItemDefaults: handleLayerDefaults
     });
 
-    // Explicitly assign `_fitBounds` (even when null) so `relinkPrivateKeys`
+    // Explicitly reset `_fitBounds` to null so that `relinkPrivateKeys`
     // doesn't carry a stale value forward from the previous render
     containerOut._fitBounds = null;
 
     // Fit the view to the data. Runs when no view attributes have
     // been set (initial render, or user cleared them) OR when they still
     // hold the exact values that were auto-computed last time. Skipped when
     // the user has explicitly opted out via `fitbounds: false`.
+    // - `_fitBounds` contains the lon/lat coords for the geometry bounding box
+    // - `_fitView` contains the view attributes after the MapLibre auto-fit has been completed
     const {
         _fitView: { center: fitCenter, zoom: fitZoom, bearing: fitBearing, pitch: fitPitch } = {},
         center,

src/plots/map/map.js

@@ -240,9 +240,10 @@ function saveViewToLayout(self, opts) {
     const { center, zoom } = self.getView();
     opts._input.center = opts.center = center;
     opts._input.zoom = opts.zoom = zoom;
-    // Use below to determine if the view is still on the fit view during supplyDefaults.
+    // Use below to determine if the current view is still on the fit view during supplyDefaults.
     // Bearing and pitch aren't set by auto-fit, but a user change to either signals
-    // they've engaged with the view and don't want it refit under them.
+    // they've engaged with the view and don't want it refit under them. `_fitView` represents
+    // the view attributes returned by MapLibre after the auto-fit has been completed.
     opts._input._fitView = {
         center: { ...center },
         zoom,