Update README

Rename Notes section
Add note on assumed pmem mount path

Author: OmSaran

README.md

@@ -118,10 +118,12 @@ where `<mode>` is one of `posix`, `sync` or `strict`.  Example: `make -C tests p
 
 Tip: Redirect stderr for less verbose output: e.g `make test 2>/dev/null`
 
-## Notes
+## Implementation Notes
 1. Only regular files, block special files and directories (only for consistency guarantees) are handled by SplitFS, the other file types are delegated to POSIX.  
 2. Only files in the persistent memory mount are handled by SplitFS, rest are delegated to POSIX.  
 Currently this is only done by examination of absolute paths specified, we aim to have this check for relative paths too, soon.
+3. Currently, the persistent memory mount is assumed to be at `/mnt/pmem_emul/`.  
+We aim to have this controlled via a runtime environment variable soon.
 
 ## License