Add guide on translating with Crowdin (#2)

* Add guide on translating with Crowdin

* Grammar fix

Co-authored-by: Albert Steppi <albert.steppi@gmail.com>

* Add join discord step to instructions

---------

Co-authored-by: Albert Steppi <albert.steppi@gmail.com>

Author: melissawm

config.yaml

@@ -35,8 +35,8 @@ params:
       url: /news/
     - title: About
       url: /about/
-#    - title: Contribute
-#      url: /contribute/
+    - title: Translate
+      url: /translate/
   footer:
     logo: logo.svg
     socialmediatitle: ""