[server-ce] update copy/logo in README (#27104)

* [server-ce] add warning on not using sandboxed compiles

Co-authored-by: Mathew Evans <matt.evans@overleaf.com>

* [server-ce] update logo

Co-authored-by: Jamie Liu <jamie.liu@overleaf.com>

---------

Co-authored-by: Mathew Evans <matt.evans@overleaf.com>
Co-authored-by: Jamie Liu <jamie.liu@overleaf.com>
GitOrigin-RevId: 9fafa951af9918924eae5493dbe8f9aa3dfc87b2

README.md

@@ -23,6 +23,11 @@
 
 [Overleaf](https://www.overleaf.com) is an open-source online real-time collaborative LaTeX editor. We run a hosted version at [www.overleaf.com](https://www.overleaf.com), but you can also run your own local version, and contribute to the development of Overleaf.
 
+> [!CAUTION]
+> Overleaf Community Edition is intended for use in environments where **all** users are trusted. Community Edition is **not** appropriate for scenarios where isolation of users is required due to Sandbox Compiles not being available. When not using Sandboxed Compiles, users have full read and write access to the `sharelatex` container resources (filesystem, network, environment variables) when running LaTeX compiles.
+
+For more information on Sandbox Compiles check out our [documentation](https://docs.overleaf.com/on-premises/configuration/overleaf-toolkit/server-pro-only-configuration/sandboxed-compiles).
+
 ## Enterprise
 
 If you want help installing and maintaining Overleaf in your lab or workplace, we offer an officially supported version called [Overleaf Server Pro](https://www.overleaf.com/for/enterprises). It also includes more features for security (SSO with LDAP or SAML), administration and collaboration (e.g. tracked changes). [Find out more!](https://www.overleaf.com/for/enterprises)