better: edn is generic

lib/linguist/languages.yml

@@ -339,15 +339,6 @@ Dart:
   type: programming
   primary_extension: .dart
 
-Datomic:
-  type: data
-  lexer: clojure
-  ace_mode: clojure
-  color: "#db5855"
-  primary_extension: .dtm
-  extensions:
-  - .dtm
-
 Delphi:
   type: programming
   color: "#b0ce4e"
@@ -394,6 +385,15 @@ Ecl:
   extensions:
   - .eclxml
 
+edn:
+  type: data
+  lexer: clojure
+  ace_mode: clojure
+  color: "#db5855"
+  primary_extension: .edn
+  extensions:
+  - .edn
+
 Eiffel:
   type: programming
   lexer: Text only