Create .gitignore

triggered by https://github.com/openstreetmap/tile-attribution/actions/runs/6918611685/job/18821042830

"output: "On branch main\nYour branch is up to date with 'origin/main'.\n\nUntracked files:\n  (use \"git add <file>...\" to include in what will be committed)\n\t.bundle/\n\tvendor/\n\nnothing added to commit but untracked files present (use \"git add\" to track)\n""

Author: matkoniecz

.gitignore

@@ -0,0 +1,2 @@
+.bundle/
+vendor/