Added: Add NLnet NGI Mobifree sponsors logo

- https://nlnet.nl/mobifree
- https://nlnet.nl/news/2024/20241111-NGI-Mobifree-grants.html
- https://termux.dev/en/posts/general/2024/11/11/termux-selected-for-nlnet-ngi-mobifree-grant.html

The `nlnet-ngi-mobifree.png` logo is sourced from https://nlnet.nl/logo

README.md

@@ -279,3 +279,8 @@ Commit messages **must** use the [Conventional Commits](https://www.conventional
 [<img alt="GitHub Secure Open Source Fund" width="25%" src="site/assets/sponsors/github.png" />](https://github.com)  
 *[GitHub Secure Open Source Fund](https://resources.github.com/github-secure-open-source-fund) ([1](https://github.blog/open-source/maintainers/securing-the-supply-chain-at-scale-starting-with-71-important-open-source-projects), [2](https://termux.dev/en/posts/general/2025/08/11/termux-selected-for-github-secure-open-source-fund-session-2.html))*
 
+&nbsp;
+
+[<img alt="NLnet NGI Mobifree" width="25%" src="site/assets/sponsors/nlnet-ngi-mobifree.png" />](https://nlnet.nl/mobifree)  
+*[NLnet NGI Mobifree](https://nlnet.nl/mobifree) ([1](https://nlnet.nl/news/2024/20241111-NGI-Mobifree-grants.html), [2](https://termux.dev/en/posts/general/2024/11/11/termux-selected-for-nlnet-ngi-mobifree-grant.html))*
+