hls, webrtc: in web page, add shadow to messages (#2959)

internal/servers/hls/index.html

@@ -34,6 +34,7 @@ html, body {
 	pointer-events: none;
 	padding: 20px;
 	box-sizing: border-box;
+	text-shadow: 0 0 5px black;
 }
 </style>
 </head>

internal/servers/webrtc/publish_index.html

@@ -64,6 +64,7 @@ select, input[type="text"] {
 	pointer-events: none;
 	padding: 20px;
 	box-sizing: border-box;
+	text-shadow: 0 0 5px black;
 }
 #publish-button {
 	margin-top: 10px;

internal/servers/webrtc/read_index.html

@@ -34,6 +34,7 @@ html, body {
 	pointer-events: none;
 	padding: 20px;
 	box-sizing: border-box;
+	text-shadow: 0 0 5px black;
 }
 </style>
 </head>