Use a default config filename

[zrhmn]

Forgive me if this is a duplicate.

It would be much appreciated if a default config filename was used, such that, if I have a config file in the root directory, like reflex.conf, I do not have to specify --config='reflex.conf' when invoking reflex. Just running reflex would automatically use my default config. (Maybe also log that reflex.conf was found, and is using that.)

If such a thing has already been implemented, I apologize, I could not find it. Please point me to it.
If such a thing can't/won't be implemented, can we discuss the reasons?

[cespare]

I'm open to a PR which treats no arguments as -c reflex.conf as a special case.

[alexsanderson]

I'll do this is we can have reflex.conf or .reflex ? (as in either present)

[cespare]

I don't like dot-prefixed files, and in general I prefer having one way to do things rather than two ways, so let's stick with just reflex.conf.