Gitignore pytest-temp-preset.json test side-effect

tests/test.py:28 (test_create_and_read_preset) calls
prettymaps.create_preset('pytest-temp-preset', ...) and writes a
real JSON file into prettymaps/presets/pytest-temp-preset.json,
which then shows up as untracked in 'git status' after running
pytest. Add a one-line gitignore rule next to the existing
prettymaps/presets/my-preset.json entry so contributors running
the test suite locally don't see a stray untracked file.

Author: marceloprates

.gitignore

@@ -44,6 +44,7 @@ SRTM1/
 *.tmp
 *.tmp.png
 prettymaps/presets/my-preset.json
+prettymaps/presets/pytest-temp-preset.json
 
 # Local-only agent guardrails (not committed)
 AGENTS.md