Add some documentation (#36)

README.md

@@ -12,3 +12,55 @@ two main purposes, the first one is to continue learning Go, and a good way to a
 projects.  I'm a [Task Warrior](https://github.com/GothenburgBitFactory/taskwarrior/) user and fan, and hence I'll doing 
 something useful at least for my personal use.  The second reason is that I think it could be interesting to have a 
 multiplatform task server that doesn't have any 3rd party libraries dependency.
+
+## Status
+
+Merge algorithm is fully implemented, tested against different task clients, and 
+[comparing](https://github.com/szaffarano/gotas/tree/master/pkg/task/testdata/payloads) 
+both taskd and gotas results. Furthermore, either the configuration files, and 
+the filesystem layout is the same, so technically, switching between taskd and 
+gotas is transparent.
+
+| Feature      | Taskd | Gotas |
+|--------------|-------|-------|
+| sync         | ✅    | ✅    |
+| init         | ✅    | ✅    |
+| add user     | ✅    | ✅    |
+| remove user  | ✅    | ❌    |
+| suspend user | ✅    | ❌    |
+| resume user  | ✅    | ❌    |
+| add org      | ✅    | ✅    |
+| remove org   | ✅    | ❌    |
+| suspend org  | ✅    | ❌    |
+| resume org   | ✅    | ❌    |
+| client api   | ✅    | ❌    |
+
+
+Disclaimer: This project is under development. Please **backup** your current 
+task server data directory to avoid any possible data loss.
+
+After **backing up** your task server data directory, stop taskd and start 
+gotas using the same syntax:
+
+```sh
+$ /path/to/gotas server --data /path/to/taskd-data/dir
+```
+
+or using `TASKDDATA` environment variable
+
+```sh
+$ export TASKDDATA="/path/to/taskd-data/dir"
+$ /path/to/gotas server
+```
+
+Gotas will read `TASKDDATA/config` file and work as expected.
+
+### Limitations
+
+- Be aware that the `--daemon` flag is not implemented yet, so gotas will run 
+  in the foreground.  
+- Because gotas only runs foreground, it only logs to stdout and stderr
+- CRL (Certificate Revocation List) validation is not implemented yet, so this 
+  configuration will be silently ignored.
+- Gotas does a full client validation (`trust=strict`), which means that this 
+  configuration will be ignored as well. Future versions will implement it.