Enhance crawlee create help to display valid options for text parameters

[vdusek]

Current behaviour

When running the crawlee create --help command, several options that accept text parameters are shown with the placeholder TEXT only, without listing their valid values:

$ crawlee create --help
╭─ Options ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ --crawler-type,--template                    TEXT  The library that will be used for crawling in your crawler. If none is given, you will be prompted.   │
│ --http-client                                TEXT  The library that will be used to make HTTP requests in your crawler. If none is given, you will be    │
│                                                    prompted.                                                                                             │
│ --package-manager                            TEXT  Package manager to be used in the new project. If none is given, you will be prompted.                │
│ --start-url                                  TEXT  The URL where crawling should start. If none is given, you will be prompted.                          │
│ --apify                      --no-apify            Should Apify integration be set up for you? If not given, you will be prompted.                       │
│ --install                    --no-install          Should the project be installed now? If not given, you will be prompted.                              │
│ --help                                             Show this message and exit.                                                                           │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯

Currently, the only way to discover the allowed values for these parameters is by invoking the command with invalid arguments and inspecting the resulting error message:

$ crawlee create --crawler-type qwe --http-client asd --package-manager zxc --start-url blahblah --no-apify --no-install my-crawler
Project creation failed: zxc provided for choice variable package_manager, but the choices are ['poetry', 'pip', 'uv'].

Proposed solution

Update the help output for crawlee create so that each text-based option lists its valid choices. For example:

--package-manager <poetry|pip|uv>    Package manager to use in the new project. If none is given, you will be prompted.