docs(startup): drop the videos made before HiNC 3.2 and the withdrawn sample download

The startup video (startup/startup.mp4) and its link, and the tutorial-video section with its
eight video links and the sample project download, are gone: the videos show versions before 3.2
and only confuse users now that 3.1 is obsolete, and the sample download is withdrawn because the
resources it carried ship in HiNC's own Resource folder.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

HiNC%E5%95%9F%E7%94%A8%E8%88%87%E6%95%99%E5%AD%B8.md

@@ -15,8 +15,6 @@
    > 除appsettings會被保留以外，其他在HiNC資料夾中的檔案變更會在更新後被刪除。
    > HiNC資料夾內如果有非系統產生的更動，有可能使得下載或更新失敗，此時可以手動刪除整個HiNC資料夾然後再次執行`HiNC-loop-with-update.bat`。
 
-   > [操作影片](startup/startup.mp4)
-
    > 如果HiNC軟件的預設載點速度太慢，可以先使用`HiNC-update-gitcode.bat`至gitcode載點下載完成後，再執行`HiNC-loop-with-update.bat`。
 
    HiNC子資料夾內可找到`appsettings.json` 檔案，該檔案用來設定HiNC組態，包含網頁位置及使用者帳號密碼等。以下以預設值說明。
@@ -74,26 +72,3 @@
 ![sentinel-firewall](startup/sentinel-firewall.jpg)
 
 > 使用紅色授權鎖，單機運行同樣需要安裝 Sentinel 授權執行環境，不是只有多主機才需要。
-
-## 教學視頻
-
-### 建立機構與刀具
-
-- https://superhightech-hinc-1.webredirect.org/download/機構建構器建立虛擬機床.mp4
-- https://superhightech-hinc-1.webredirect.org/download/建立臥式機床.mp4
-- https://superhightech-hinc-1.webredirect.org/download/刀具建立-銑削與刀把.mp4
-
-### 專案設定與執行
-
-1. https://superhightech-hinc-1.webredirect.org/download/範例專案設置說明.mp4
-2. https://superhightech-hinc-1.webredirect.org/download/範例專案仿真說明.mp4
-3. https://superhightech-hinc-1.webredirect.org/download/建立專案.mp4
-
-> **範例專案下載**
-> https://superhightech-gitea.webredirect.org/HiNC-Deploy/DemoStandardPath/archive/master.zip
-
-### 進階操作
-
-- https://superhightech-hinc-1.webredirect.org/download/串聯控制器感測器解譯器映射.mp4
-- https://superhightech-hinc-1.webredirect.org/download/工藝視覺化範例.mp4
-