Add introduction section to macosvfs docs

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

doc/macosvfs.rst

@@ -5,3 +5,35 @@ macOS Virtual Files
 ====
 
 .. index:: macosvfs
+
+Introduction
+============
+
+Virtual file-based synchronisation for Nextcloud desktop users is now
+available on macOS.
+
+Unlike on Windows, virtual files support on macOS is provided by a
+separate client version. This allows us to maintain the best possible
+experience for classically-synced files, including sync status
+integration and context menu actions, for users who want to keep using
+this sync method. Just like our classic sync client, the macOS virtual
+files client is released alongside the desktop client for Windows and
+Linux, and will benefit from regular bug-fix and feature updates that
+improve the user experience.
+
+Supported features
+------------------
+
+- Per-file local retention and eviction
+- Intelligent local copy eviction
+- Integration with Spotlight
+- File previews within Finder for virtual files
+- Support for Apple-specific formats such as app bundles and iWork
+  (Pages, Numbers, Keynote) bundles
+- Remote file locking compatibility
+- “Edit locally” support
+- File sharing with other users
+- Automatic synchronisation of remote changes **NOTE: we recommend the
+  use of ``notify_push`` on the server!**
+- More!
+