Add valid values for the preload attribute for audio/video elements

src/vs/languages/html/common/htmlTags.ts

@@ -92,8 +92,8 @@ export function getHTML5TagProvider(): IHTMLTagProvider {
 		embed: ['src', 'type', 'width', 'height'],
 		object: ['data', 'type', 'typemustmatch:v', 'name', 'usemap', 'form', 'width', 'height'],
 		param: ['name', 'value'],
-		video: ['src', 'crossorigin:xo', 'poster', 'preload', 'autoplay:v', 'mediagroup', 'loop:v', 'muted:v', 'controls:v', 'width', 'height'],
-		audio: ['src', 'crossorigin:xo', 'preload', 'autoplay:v', 'mediagroup', 'loop:v', 'muted:v', 'controls:v'],
+		video: ['src', 'crossorigin:xo', 'poster', 'preload:pl', 'autoplay:v', 'mediagroup', 'loop:v', 'muted:v', 'controls:v', 'width', 'height'],
+		audio: ['src', 'crossorigin:xo', 'preload:pl', 'autoplay:v', 'mediagroup', 'loop:v', 'muted:v', 'controls:v'],
 		source: ['src', 'type'],
 		track: ['default:v', 'kind:tk', 'label', 'src', 'srclang'],
 		canvas: ['width', 'height'],
@@ -165,6 +165,7 @@ export function getHTML5TagProvider(): IHTMLTagProvider {
 		bt: ['button', 'submit', 'reset'],
 		lt: ['1', 'a', 'A', 'i', 'I'],
 		tk: ['subtitles', 'captions', 'descriptions', 'chapters', 'metadata'],
+		pl: ['none', 'metadata', 'auto'],
 		xo: ['anonymous', 'use-credentials'],
 		sb: ['allow-forms', 'allow-modals', 'allow-pointer-lock', 'allow-popups', 'allow-popups-to-escape-sandbox', 'allow-same-origin', 'allow-scripts', 'allow-top-navigation'],
 		tristate: ['true', 'false', 'mixed', 'undefined'],