Documentation in readme for allowed parameter values

[jmlord]

It would be great to include the allowed parameter values in the GitHub read-me. When setting parameters for a production server I had to guess or search many of them in the Discourse forum for that kind of information.

Example of questions that this documentation would avoid:

• --api-keys is a flag. On the command line it's obvious. But when using LT_API_KEYS, is defining it enough? Should I put true?
• Is LT_REQUIRE_API_KEY_ORIGIN a toggle, with the origin automatically detected? Or a string? I which case, can I put a wildcard there such as *.mydomain.com ?

[pierotofy]

I think any value with LT_API_KEYS will do (e.g. LT_API_KEYS=ON or LT_API_KEYS=1).

LT_REQUIRE_API_KEY_ORIGIN is a string (regex), so to match a wildcard it should be something like .*.mydomain.com

if re.match(args.require_api_key_origin, request.headers.get("Origin", ""):

We'd love help improving the README.