fix: cannot display MARK Underlined in minimap (microsoft#226116)

Fixed: microsoft#226114

After testing, there are no issues in Firefox, but in Chrome, lines with a lineWidth less than 0.3 will not be displayed. Some lines won't show if it is less than 0.4. It will only display normally if it is greater than or equal to 0.4.

Codepen Test: https://codepen.io/blackhole1/pen/QWXmGYB

Signed-off-by: Kevin Cui <[email protected]>

Author: BlackHole1

src/vs/editor/browser/viewParts/minimap/minimap.ts

@@ -1844,7 +1844,7 @@ class InnerMinimap extends Disposable {
 		canvasContext.letterSpacing = sectionHeaderLetterSpacing + 'px';
 		canvasContext.font = '500 ' + sectionHeaderFontSize + 'px ' + this._model.options.sectionHeaderFontFamily;
 		canvasContext.strokeStyle = separatorStroke;
-		canvasContext.lineWidth = 0.2;
+		canvasContext.lineWidth = 0.4;
 
 		const decorations = this._model.getSectionHeaderDecorationsInViewport(layout.startLineNumber, layout.endLineNumber);
 		decorations.sort((a, b) => a.range.startLineNumber - b.range.startLineNumber);