docs(pr-assets): add screenshots for the line-ending indicator PR

Terminal captures (tmux) illustrating the new whitespace_newlines /
whitespace_carriage_returns options for PR #2800: CRLF and LF buffers
with indicators on, the same CRLF buffer with the default (off) config,
and the Settings UI entries. Referenced from the PR description; safe
to drop before merge if unwanted in-tree.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rBfqYynfutZdebh9hbZHG

Author: claude