Updated Translation (markdown)

Translation.md

@@ -5,9 +5,14 @@ The translation concept follows similar concepts as GNU gettext:
 - As message IDs we use the original sentences in English. Therefore any untranslated messages will fall back to English and no English translation files need to be added.
 - Plural forms are supported.
 
-## How to translate
+## TL;DR: How to translate
 
-tl;dr: Go into the directory `i18n`. Copy any of the files into your languages [two-letter ISO 639-1 code](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes#Partial_ISO_639_table), i.e. to `es.json` for a Spanish. Open the file in a text editor and change the messages after the english message ID. Save the file in UTF-8 character encoding. Done. (Pull requests highly welcome!)
+1. Go into the directory `i18n`.
+2. Copy one of the files into your languages [two-letter ISO 639-1 code](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes#Partial_ISO_639_table), i.e. to `es.json` for a Spanish.
+3. Open the file in a text editor and change the messages after the english message ID.
+4. Save the file in UTF-8 character encoding.
+5. Add your new language code into the array called `supportedLanguages` in `lib/zerobin.js` (around line 300).
+6. Done (Pull requests highly welcome!)
 
 ## Technical Details
 
@@ -31,4 +36,19 @@ Many languages use plural forms and some even more then one. For number dependen
     [...]
     }
 
-Some languages can have more then one plural forms. Which form to use depending on a given number is [decided based on a formula](http://localization-guide.readthedocs.org/en/latest/l10n/pluralforms.html).
+Some languages can have more then one plural forms. Which form to use depending on a given number is [decided based on a formula](http://localization-guide.readthedocs.org/en/latest/l10n/pluralforms.html).
+
+### Gotchas
+
+Currently we do not inform the JS part about the available languages on the server, but instead these are statically encoded in the file `lib/zerobin.js` in the property `i18n.supportedLanguages` (around line 300). If you add a new language, remember to add it there, too.
+
+For the language labels displayed in the optional language selection drop down menu, a file called `i18n/languages.json` was created. Most languages should already be included with a translated language label and its English translation.
+
+If you provide translations for one of the languages not included in the list, you need to add it in there. Create a new property with a (not yet existing) ISO code and the language labels in its native form and translated to English, as in the example below:
+
+    {
+    [...]
+        "qp": ["tlhIngan Hol", "Klingon"],
+        "13": ["1337 5934|<", "Leetspeak"],
+    [...]
+    }