add velero.io site content, move docs to under site/docs (#1489)

* Adding in Jekyll site | Adjusting gitignore for Jekyll build | Moving docs to site folder

Signed-off-by: Lee Springer <lee@smalltalk.agency>

Adding in Jekyll site | Adjusting gitignore for Jekyll build | Moving docs to site folder

Signed-off-by: Lee Springer <lee@smalltalk.agency>

* Restore main.go to original location

Signed-off-by: Lee Springer <lee@smalltalk.agency>

* Updates to footer

Signed-off-by: Lee Springer <lee@smalltalk.agency>

* Updates to homepage links

Signed-off-by: Lee Springer <lee@smalltalk.agency>

* Content updates

Signed-off-by: Lee Springer <lee@smalltalk.agency>

site/_plugins/tag_page_generator.rb

@@ -0,0 +1,32 @@
+module Jekyll
+
+    class TagPage < Page
+      def initialize(site, base, dir, tag)
+        @site = site
+        @base = base
+        @dir = dir
+        @name = 'index.html'
+  
+        self.process(@name)
+        self.read_yaml(File.join(base, '_layouts'), 'tag-index.html')
+        self.data['tag'] = tag
+  
+        tag_title_prefix = site.config['tag_title_prefix'] || 'Posts by '
+        self.data['title'] = "#{tag_title_prefix}#{tag}"
+      end
+    end
+  
+    class TagPageGenerator < Generator
+      safe true
+  
+      def generate(site)
+        if site.layouts.key? 'tag-index'
+          dir = site.config['tag_dir'] || 'tags'
+          site.tags.keys.each do |tag|
+            site.pages << TagPage.new(site, site.source, File.join(dir, tag), tag)
+          end
+        end
+      end
+    end
+  
+  end