Add CLI arguments to config file

The log level can now be set with `log_level` (accepts ints and strings).
The log file can now be set with `output` (also accepts `STDOUT`).

src/invidious/helpers/logger.cr

@@ -1,14 +1,14 @@
 require "logger"
 
 enum LogLevel
-  All
-  Trace
-  Debug
-  Info
-  Warn
-  Error
-  Fatal
-  Off
+  All   = 0
+  Trace = 1
+  Debug = 2
+  Info  = 3
+  Warn  = 4
+  Error = 5
+  Fatal = 6
+  Off   = 7
 end
 
 class Invidious::LogHandler < Kemal::BaseLogHandler