Update README.md
Fix description about annotaion
@@ -50,7 +50,7 @@ cargo build --release
- `s`: `task {selected} start/stop` - Toggle start and stop
- `u`: `task undo` - Undo
- `x`: `task delete {selected}` - Delete
-- `A`: `task {selected} annotate {string}` - Add new task
+- `A`: `task {selected} annotate {string}` - Annotate current task
- `?`: `help` - Help menu
![taskwarrior-tui](https://user-images.githubusercontent.com/1813121/88654924-40896880-d08b-11ea-8709-b29cc970da4c.gif)
