docs: add dirsync module to root README

README.md

@@ -25,6 +25,12 @@ cd dbutils_mongo && ./db-start.sh up
 cd dbrestore_mongo && ./db-restore.sh
 ```
 
+### File Sync
+
+| Script | Description |
+|---|---|
+| [`dirsync/`](dirsync/) | Watch a local directory and sync changes to a remote host via SCP in real time |
+
 ## Requirements
 
 Each script lists its own requirements in its README. Common dependencies:
@@ -32,6 +38,7 @@ Each script lists its own requirements in its README. Common dependencies:
 - **Bash**
 - **MongoDB Database Tools** (`mongodump` / `mongorestore`) — [download](https://www.mongodb.com/try/download/database-tools)
 - **Docker & Docker Compose** (for `dbutils_mongo` only)
+- **fswatch + ssh + scp** (for `dirsync` only)
 
 ## Author