Create elvis.config.sample file

[ferigis]

with all the available fields. Related to [#437]

[paulo-ferraz-oliveira]

Is the Rules wiki enough for this? Or should we consider a different location for this file? I don't mind tackling this issue. I might even learn a few new things about elvis.

[elbrujohalcon]

We should add something like this to that wiki to solve the issue…

[
 {
   elvis,
   [
    {config,
     [#{dirs => ["src"],
        filter => "*.erl",
        ruleset => erl_files,
        rules => [
            % your exceptional rules
        ]
      },
      #{dirs => ["test"],
        filter => "*.erl",
        ruleset => erl_files,
        rules => [
            % your exceptional rules
        ]
      },
      #{dirs => ["."],
        filter => "elvis.config",
        ruleset => elvis_config,
        rules => [
            % your exceptional rules
        ]
      },
      …
     ]
    }
   ]
 }
].

The idea being that someone can just add that elvis.config to their project and then tune it.

[elbrujohalcon]

with all possible entries (i.e. one for rebar.confg, one for Makefile, I guess…)

[paulo-ferraz-oliveira]

I added the example elvis.config section here: https://github.com/inaka/elvis_core/wiki/Rules#example-elvisconfig. I'm going to review the rules now.

[elbrujohalcon]

Excellent!!