feat(#297): New rule: Prefer Unquoted Atoms

RULES.md

@@ -61,6 +61,7 @@ identified with `(since ...)` for convenience purposes.
 - [State Record and Type](doc_rules/elvis_style/state_record_and_type.md)
 - [Used Ignored Variable](doc_rules/elvis_style/used_ignored_variable.md)
 - [Variable Naming Convention](doc_rules/elvis_style/variable_naming_convention.md)
+- [Prefer Unquoted Atoms](doc_rules/elvis_style/prefer_unquoted_atoms.md)
 
 ## Project rules
 

doc_rules/elvis_style/prefer_unquoted_atoms.md

@@ -0,0 +1,15 @@
+# Prefer unquoted atoms
+
+Do not use quotes on atoms that are not need it.
+
+> Works on `.beam` file? No.
+
+## Options
+
+- None.
+
+## Example
+
+```erlang
+{elvis_style, prefer_unquoted_atoms, #{}}
+```