Add s tag for strikethrough

Thanks @fauno in xijo#76

CHANGELOG.md

@@ -1,6 +1,9 @@
 # Change Log
 All notable changes to this project will be documented in this file.
 
+## 1.3.0 - September 2019
+- Add support for `s` HTML tag, thanks @fauno
+
 ## 1.2.0 - August 2019
 - Handle windows `\r\n` within text blocks, thanks for reporting @krisdigital
 - Handle paragraphs in `li` tags, thanks @gstamp

lib/reverse_markdown/converters/del.rb

@@ -20,6 +20,7 @@ def disabled?
     end
 
     register :strike, Del.new
+    register :s,      Del.new
     register :del,    Del.new
   end
 end

lib/reverse_markdown/version.rb

@@ -1,3 +1,3 @@
 module ReverseMarkdown
-  VERSION = '1.2.0'
+  VERSION = '1.3.0'
 end

spec/lib/reverse_markdown/converters/del_spec.rb

@@ -11,6 +11,11 @@
       expect(converter.convert(input)).to eq '~~deldeldel~~'
     end
 
+    it 'converts the input as expected' do
+      input = node_for('<s>strike that</s>')
+      expect(converter.convert(input)).to eq '~~strike that~~'
+    end
+
     it 'skips empty tags' do
       input = node_for('<del></del>')
       expect(converter.convert(input)).to eq ''