Add complimentary instructions and information for translating

CONTRIBUTING.md

@@ -46,4 +46,49 @@ Translations to other languages are highly encouraged but handled a little diffe
 We now keep each translation in a separate repository.
 
 Since each translation is a different repository, we can also have different maintainers for each project.
-The Pro Git team simply pulls them in and builds them for the translation teams.
+The Pro Git team simply pulls them in and builds them for the translation teams on the git-scm.com website.
+
+### Existing Projects
+
+If you wish to help at translating Progit 2nd edition to your
+language, first check already existing projects and get in touch with
+the people in charge of them if there's already one.
+
+Existing projects include:
+
+  Language   |   Project
+------------ | -------------
+Беларуская  | [progit/progit2-be](https://github.com/progit/progit2-be)
+Čeština    | [progit-cs/progit2-cs](https://github.com/progit-cs/progit2-cs)
+English    | [progit/progit2](https://github.com/progit/progit2)
+Español    | [progit/progit2-es](https://github.com/progit/progit2-es)
+Français   | [progit/progit2-fr](https://github.com/progit/progit2-fr)
+Ελληνικά   | [progit2-gr/progit2](https://github.com/progit2-gr/progit2)
+Indonesian | [progit/progit2-id](https://github.com/progit/progit2-id)
+Italiano   | [progit/progit2-it](https://github.com/progit/progit2-it)
+日本語   | [progit/progit2-ja](https://github.com/progit/progit2-ja)
+한국어   | [progit/progit2-ko](https://github.com/progit/progit2-ko)
+Nederlands | [progit/progit2-nl](https://github.com/progit/progit2-nl)
+Português (Brasil) | [progit2-pt-br/progit2](https://github.com/progit2-pt-br/progit2)
+Русский   | [progit/progit2-ru](https://github.com/progit/progit2-ru)
+Slovenščina  | [progit/progit2-sl](https://github.com/progit/progit2-sl)
+Српски   | [progit/progit2-sr](https://github.com/progit/progit2-sr)
+Türkçe   | [progit/progit2-tr](https://github.com/progit/progit2-tr)
+Українська| [progit/progit2-uk](https://github.com/progit/progit2-uk)
+Ўзбекча  | [progit/progit2-uz](https://github.com/progit/progit2-uz)
+简体中文  | [progit/progit2-zh](https://github.com/progit/progit2-zh)
+正體中文  | [progit/progit2-zh-tw](https://github.com/progit/progit2-zh-tw)
+
+### Your Language does not Exist
+
+Then you're lucky! You're gonna be the initiator of a new translation project!
+
+You can start to make your own version with the second edition in English, available here. To do so,
+
+ 1. Pick your the [ISO 639 code](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes) and create a GitHub organization, say `progit2-[your code]` on github
+ 2. Create a project progit2
+ 3. Copy the structure of progit/progit2 (this project) in your project and start translating. You can reuse some material from the first edition, but beware that:
+    1. the text has been reworked in numerous parts
+    2. the markup has changed from markdown to [asciidoc](http://asciidoc.org)
+ 4. Push to the new repo a few translated chapters
+ 5. Ping an organizer so that the second edition of Progit in your language is pushed on git-scm.com.