chore: 首次簽入 Thinkyu ASP.NET 專案

- 加入 Visual Studio / ASP.NET .gitignore
- 排除建置輸出、IDE 設定、NuGet packages、大型 MSI 安裝檔

教育訓練系統/Web/Forms/Common/ShowContent.aspx

@@ -0,0 +1,6 @@
+<%@ Page Title="" Language="C#" MasterPageFile="~/PopupForm2.Master" AutoEventWireup="true" CodeBehind="ShowContent.aspx.cs" Inherits="Education.Forms.辦訓前置作業.ShowContent" %>
+<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
+</asp:Content>
+<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
+  <asp:Label ID="Label1" runat="server"></asp:Label>
+</asp:Content>