added bootstrap

public/bootstrap-4.0.0/_plugins/markdown-block.rb

@@ -0,0 +1,20 @@
+module Jekyll
+  class MarkdownBlock < Liquid::Block
+    alias_method :render_block, :render
+
+    def initialize(tag_name, markup, tokens)
+      super
+    end
+
+    # Uses the default Jekyll markdown parser to
+    # parse the contents of this block
+    #
+    def render(context)
+      site = context.registers[:site]
+      converter = site.find_converter_instance(::Jekyll::Converters::Markdown)
+      converter.convert(render_block(context))
+    end
+  end
+end
+
+Liquid::Template.register_tag('markdown', Jekyll::MarkdownBlock)