text: Title: ploomber examples into local directory
  Body: When running !ploomber examples -n guides/spec-api-python -o . it outputs an error:
  
  Local copy does not exist...
  Cloning into '/root/.ploomber/projects'...
  remote: Enumerating objects: 416, done.
  remote: Counting objects: 100% (416/416), done.
  remote: Compressing objects: 100% (335/335), done.
  remote: Total 416 (delta 64), reused 283 (delta 34), pack-reused 0
  Receiving objects: 100% (416/416), 1.31 MiB | 8.96 MiB/s, done.
  Resolving deltas: 100% (64/64), done.
  ================= Copying example guides/spec-api-python to ./ =================
  Error: '.' already exists in the current working directory, please rename it or move it to another location and try again.
  