Translations and i18n (#60)

* Managing i18n

* Fix absolute path

* Config files

* Home link manage langage

* Fixing footer i18n

* Implemented i18n on newsletter

* Implemented two languages in example

* Removed old section directory

* Using yaml in data to organize home summary

* Fully working for old versions without i18n

* Integrating language menu CSS

* Fix language dropdown CSS

* Refactor translation codes

* Remove duplicate code

* Fix URL issues

* Move customMenus and other site related config into data section

* Fix error during language toggle

* Only show the available translation for the posts

* Handle navbar brand URL properly

* Fix responsiveness

Co-authored-by: Hugo MARTIN <hugo.martin.69@gmail.com>
Co-authored-by: hossainemruz <emruz@appscode.com>

exampleSite/data/en/sections/achievements.yaml

@@ -0,0 +1,23 @@
+# section information
+section:
+  name: Achievements
+  enable: true
+  weight: 6
+  showOnNavbar: true
+  # Can optionally hide the title in sections
+  # hideTitle: true
+
+# Your achievements achievements
+achievements:
+- title: Best Presenter
+  image: images/achievements/presenter.jpg
+  summary: Best presenter in the 2020 XYZ conference.
+- title: Champion
+  image: images/achievements/sport.jpg
+  summary: Champion in cycling inter-city cycling championship 2020.
+- title: Graduation
+  image: images/achievements/graduation-cap.jpg
+  summary: Received Bachelor of Science (B.Sc.) in Computer Science and Engineer from XYZ University.
+- title: Award Winner
+  image: images/achievements/woman-winner.jpg
+  summary: Lorem ipsum dolor sit amet consectetur adipisicing elit. Possimus architecto minus facere vero?