Add Pod 6 to the languages.yml (#4083)

* Add pod6 to the languages.yml

* Add tm_source to pod6 language entry

* Updated grammar list

* Add heuristics for pod vs pod6

* Add a language_id for Pod6

* Rename 'Pod6' to 'Pod 6'

* Update the grammar list

* Set Pod 6 ace_mode to 'perl' instead of 'perl6' to pass test

* Add sample for Pod 6

* Update heuristics to use Pod 6 instead of Perl 6

* Remove .pod6 as a Pod 6 extension

* Extend Pod 6 heuristics

Both "=begin pod" and "=comment" are Pod 6 unique constructs. As such,
these can be used to differentiate between Pod and Pod 6.

* Merge two regexes in one for Pod 6 heuristics

* Update whitespace match to match all whitespace except newlines

* Remove excessive =

* Add sample POD file for heuristics test

* Update Pod 6 heuristics to default to Pod

* Update Pod 6 heuristics

lib/linguist/heuristics.rb

@@ -380,6 +380,16 @@ def call(data)
       end
     end
 
+    disambiguate ".pod" do |data|
+      if /^\s*\/\* XPM \*\//.match(data)
+        Language["XPM"]
+      elsif /^[\s&&[^\n]]*=(comment|begin pod|begin para|item\d+)/.match(data)
+        Language["Pod 6"]
+      else
+        Language["Pod"]
+      end
+    end
+
     disambiguate ".pro" do |data|
       if /^[^\[#]+:-/.match(data)
         Language["Prolog"]

lib/linguist/languages.yml

@@ -3495,6 +3495,16 @@ Pod:
   - perl
   tm_scope: none
   language_id: 288
+Pod 6:
+  type: prose
+  ace_mode: perl
+  tm_scope: source.perl6fe
+  wrap: true
+  extensions:
+  - ".pod"
+  interpreters:
+  - perl6
+  language_id: 155357471
 PogoScript:
   type: programming
   color: "#d80074"