Added an introduction and an onboarding chat to the BeyondFacts Lab (#1178)

app/MindWork AI Studio/Assistants/BeyondFactsLab/BflIntroduction.razor.cs

@@ -0,0 +1,19 @@
+using AIStudio.Components;
+
+namespace AIStudio.Assistants.BeyondFactsLab;
+
+/// <summary>
+/// Tells how to work with the BeyondFacts Lab: what it is for and what not, how long a preparation takes, how to
+/// proceed, and how to recognize good results.
+/// </summary>
+/// <remarks>
+/// The texts follow the short guide for users by Lara Wüster. They describe the lab as this version has it, so a
+/// change of the lab may need a change here as well, and in the prompt of the onboarding.
+/// </remarks>
+public partial class BflIntroduction : MSGComponentBase
+{
+    /// <summary>
+    /// Puts the icon of a list item at the first line of its text, like MudTextList does.
+    /// </summary>
+    private const string LIST_ITEM_STYLE = "display: flex; align-items: flex-start;";
+}