set tips size via query string in app

This moves the "small" font size from CSS into the URL the
application uses for the tips. This way, the tips appear at a more
reasonable size when viewed in a web browser (where they are useful
since they have nice section and "topic" links).

I tested this with 100% and 125% scaling and it seems to work fine.

The code change also leads the way for a possible future feature
where the tips size is configurable. (I don't know if I'll implement
that though.)

doc/tips.css

@@ -1,7 +1,6 @@
 body {
   cursor: default;
   font-family: 'Segoe UI', 'Nimbus Sans L', 'DM Sans', 'Selawik', '-apple-system', system-ui, 'BlinkMacSystemFont', 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif;
-  font-size: small;
   font-variant-numeric: tabular-nums;
   margin: 0;
 }

flood.linq

@@ -2366,7 +2366,8 @@ internal sealed class TipsViewer : MyWebBrowser {
         if (e.Url.SchemeIs(Uri.UriSchemeFile)) HelpRequest?.Invoke(this, e);
     }
 
-    private readonly Uri _home = Files.GetDocUrl("tips.html");
+    private readonly Uri _home =
+        Files.GetDocUrl(filename: "tips.html", query: "size=small");
 }
 
 /// <summary>
@@ -2546,7 +2547,10 @@ internal delegate Task<HelpViewer> HelpViewerSupplier();
 /// </summary>
 internal static class Files {
     internal static Uri GetDocUrl(string filename)
-        => new(Path.Combine(QueryDirectory, "doc", filename));
+        => new(GetDocPath(filename));
+
+    internal static Uri GetDocUrl(string filename, string query)
+        => new UriBuilder(GetDocPath(filename)) { Query = query }.Uri;
 
     internal static string GetSystem32ExePath(string basename)
         => Path.Combine(WindowsDirectory, "system32", $"{basename}.exe");
@@ -2639,6 +2643,9 @@ internal static class Files {
         return bitmap;
     }
 
+    private static string GetDocPath(string filename)
+        => Path.Combine(QueryDirectory, "doc", filename);
+
     private static string GetImagePath(string filename)
         => Path.Combine(QueryDirectory, "images", filename);