Task(1010245): Update README.md files in the all the samples

[Ranjani4311]

Update the ReadMe files

Update all sample README files to include step-by-step instructions for downloading samples using DownGit.

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Steps to download GitHub samples using DownGit

1. Open the DownGit Website

   Go to the official DownGit tool: https://downgit.github.io/#/home

2. Copy the GitHub URL

   • Navigate to the sample folder you want to download and copy its URL.
   • Example : https://github.com/SyncfusionExamples/ej2-react-grid-samples/tree/master/connecting-to-backends/syncfusion-reactgrid-with-django-server

3. Paste the URL into DownGit

   In the DownGit input box, paste the copied GitHub URL.

4. Download the ZIP

   • Click Download.
   • DownGit will generate a ZIP file of the selected folder, which you can save and extract locally.