[string_preprocessing] When splitting lines, `\n` is ignored

message = (
    "1. Go to Google Developers Console and log in with your favourite Google account.\n"
    "(https://console.developers.google.com/)\n"
    "2. You should be prompted to create a new project (name does not matter).\n"
    "3. Click on Enable APIs and Services at the top.\n"
    "4. In the list of APIs choose or search for YouTube Data API v3 and "
    "click on it. Choose Enable.\n"
    "5. Click on Credentials on the left navigation bar.\n"
    "6. Click on Create Credential at the top.\n"
    '7. At the top click the link for "API key".\n'
    "8. No application restrictions are needed. Click Create at the bottom.\n"
    "9. You now have a key to add to `[p]set api youtube api_key <your_api_key_here>`"
)

message = (
    "1. Go to Google Developers Console and log in with your favourite Google"
    " account.\n(https://console.developers.google.com/)\n2. You should be prompted to"
    " create a new project (name does not matter).\n3. Click on Enable APIs and"
    " Services at the top.\n4. In the list of APIs choose or search for YouTube Data"
    " API v3 and click on it. Choose Enable.\n5. Click on Credentials on the left"
    " navigation bar.\n6. Click on Create Credential at the top.\n7. At the top click"
    ' the link for "API key".\n8. No application restrictions are needed. Click Create'
    " at the bottom.\n9. You now have a key to add to `[p]set api youtube api_key"
    " <your_api_key_here>`"
)

message = (
    "1. Go to Google Developers Console and log in with your favourite"
    " Google account.\n"
    "(https://console.developers.google.com/)\n"
    "2. You should be prompted to create a new project (name does not matter).\n"
    "3. Click on Enable APIs and Services at the top.\n"
    "4. In the list of APIs choose or search for YouTube Data API v3 and "
    "click on it. Choose Enable.\n"
    "5. Click on Credentials on the left navigation bar.\n"
    "6. Click on Create Credential at the top.\n"
    '7. At the top click the link for "API key".\n'
    "8. No application restrictions are needed. Click Create at the bottom.\n"
    "9. You now have a key to add to `[p]set api youtube api_key <your_api_key_here>`"
)