-path-aliases is ignored when using -cwd-mode plain

[staenker]

Describe the bug
when using -cwd-mode plain -path-aliases logic is not executed

To Reproduce
Steps to reproduce the behavior:

• Open source code file: segment-cwd.go
• Follow this logic:
  The only reference to method maybeAliasPathSegments is from within cwdToPathSegments on line 139.
  The only reference to method cwdToPathSegments is from within segmentCwd on line 183.
  handling of case "plain" happens in lines 172-181 - so before line 183, so maybeAliasPathSegments is not called in that case.

Expected behavior
Either a faint hint in the docs that -path-aliases is not working when using -cwd-mode plain. Or make use of the logic in maybeAliasPathSegments in case of -cwd-mode plain (in lines 172-181)

Environment (please complete the following information):
not important in this case

Additional context
not important in this case