Usage:
  ./gott [flags]

Flags:
  -d value
    	Define variables, syntax: NAME[:TYPE[:TYPE]]=VALUE
  -f string
    	Input file name or - for stdin (default "-")
  -o string
    	Output file name or - for stdout (default "-")
  -v	Print the version

Variable types:
  bool    - boolean, uses Go's strconv.ParseBool
  env     - string, read value from environment variable (chainable)
  file    - string, read value from utf-8 file (chainable)
  float   - float64, uses Go's strconv.ParseFloat
  float64 - float64, uses Go's strconv.ParseFloat
  int     - int64, uses Go's strconv.ParseInt
  int64   - int64, uses Go's strconv.ParseInt
  json    - any, uses Go's encoding/json.Unmarshal
  string  - string

Variable definition examples:
  -d 'name=John'                         - define "name" string variable with "John" as value
  -d 'debug:bool=false'                  - define "debug" boolean variable with false as value
  -d 'config:json:file=/etc/config.json" - read file "/etc/config.json", parse it as json, save the result to "config" variable
  -d 'IsRelease:bool:env=IS_RELEASE"     - read environment variable "IS_RELEASE", parse it as bool, save the result to "IsRelease" variable
  -d 'a=1' -d 'b=2'                      - define multiple variables

  It's easiest to read it from right to left: NAME:A:B=VALUE - VALUE is applied to type B, then to type A, then saved as NAME.
  Variables are available from the top level template context object, e.g. {{ if .IsRelease }}RELEASE{{ else }}DEBUG{{ end }}