CLI flags, start setting up goreleaser, add build scripts

Copied and fixed the build scripts from jf-accounts, added them to the
.goreleaser.yml. Also:
data directory now stored in user's config folder
Handle timeouts in jfapi
Maybe more i forgot about.

README.md

@@ -1,5 +1,11 @@
 # jfa-go
 
-An ongoing rewrite of [jellyfin-accounts](https://github.com/hrfee/jellyfin-accounts) in Go. I'm doing this to learn the language, so i'll still be maintaining the Python version.
+A rewrite of [jellyfin-accounts](https://github.com/hrfee/jellyfin-accounts) in Go. Should be fully functional, and functions the same as jf-accounts. To switch, copy your existing `~/.jf-accounts` to:
+
+* `XDG_CONFIG_DIR/jfa-go` (usually ~/.config) on \*nix systems, 
+* `%AppData%/jfa-go` on Windows,
+* `~/Library/Application Support/jfa-go` on macOS.
+
+(*or specify config/data path  with `-config/-data` respectively.*)
 
 Suggestions and help welcome.