make anchor setting experimental and refine descriptions

Author: amunger

src/vs/workbench/contrib/notebook/browser/notebook.contribution.ts

@@ -1031,11 +1031,13 @@ configurationRegistry.registerConfiguration({
 			default: 'fullCell'
 		},
 		[NotebookSetting.anchorToFocusedCell]: {
-			markdownDescription: nls.localize('notebook.scrolling.anchorToFocusedCell.description', "Keep the focused cell steady while surrounding cells change size"),
+			markdownDescription: nls.localize('notebook.scrolling.anchorToFocusedCell.description', "Keep the focused cell steady while surrounding cells change size."),
 			type: 'string',
-			enum: ['auto', 'true', 'false'],
+			enum: ['auto', 'on', 'off'],
 			markdownEnumDescriptions: [
-				nls.localize('notebook.scrolling.anchorToFocusedCell.auto.description', "Anchor to the focused cell when the resized cell is partially visible unless {0} is set to {1}", 'notebook.scrolling.revealCellBehavior', 'none')
+				nls.localize('notebook.scrolling.anchorToFocusedCell.auto.description', "Anchor the viewport to the focused cell depending on context unless {0} is set to {1}.", 'notebook.scrolling.revealCellBehavior', 'none'),
+				nls.localize('notebook.scrolling.anchorToFocusedCell.on.description', "Always anchor the viewport to the focused cell."),
+				nls.localize('notebook.scrolling.anchorToFocusedCell.off.description', "The focused cell may shift around as cells resize.")
 			],
 			default: 'auto'
 		}

src/vs/workbench/contrib/notebook/browser/view/notebookCellList.ts

@@ -1208,7 +1208,7 @@ export class NotebookCellList extends WorkbenchList<CellViewModel> implements ID
 		const anchorFocusedSetting = this.configurationService.getValue(NotebookSetting.anchorToFocusedCell);
 		const allowScrolling = this.configurationService.getValue(NotebookSetting.scrollToRevealCell) !== 'none';
 		const scrollHeuristic = allowScrolling && anchorFocusedSetting === 'auto' && this.view.elementTop(index) < this.view.getScrollTop();
-		if (focused && (anchorFocusedSetting === 'true' || scrollHeuristic)) {
+		if (focused && (anchorFocusedSetting === 'on' || scrollHeuristic)) {
 			this.view.updateElementHeight(index, size, focus);
 		}
 

src/vs/workbench/contrib/notebook/common/notebookCommon.ts

@@ -965,7 +965,7 @@ export const NotebookSetting = {
 	remoteSaving: 'notebook.experimental.remoteSave',
 	gotoSymbolsAllSymbols: 'notebook.gotoSymbols.showAllSymbols',
 	scrollToRevealCell: 'notebook.scrolling.revealCellBehavior',
-	anchorToFocusedCell: 'notebook.scrolling.anchorToFocusedCell'
+	anchorToFocusedCell: 'notebook.scrolling.experimental.anchorToFocusedCell'
 } as const;
 
 export const enum CellStatusbarAlignment {