Update README.md

Clarify planned features, we wouldn't want the model to have free access
to read any file in the system.

README.md

@@ -6,10 +6,12 @@ Current features:
 - Perform one-shot prompts with `lmcli prompt <message>`
 - Manage persistent conversations with the `new`, `reply`, `view`, and `rm`
   sub-commands.
+- Syntax highlighted output
 
 Planned features:
 - Ask questions about content received on stdin
-- "functions" to allow reading (and possibly writing) to local files
+- "functions" to allow reading (and possibly writing) to files within the
+  current working directory
 
 Maybe features:
 - Natural language image generation, iterative editing