Add key value file definition

- add .kv file standard definition
- move test documentation to "doc" folder

doc/kv_file_definition.md

@@ -0,0 +1,13 @@
+# Key Value File - Definition #
+
+This document defines the standard of a key value file (__.kv__).
+
+1. A Key Value File needs to have the file extension "__.kv__".
+2. A Key Value Pair, which is defined in such a file, has the following format:
+   ```
+   port=8080;
+   ```
+   The key is defined at the beginning of a line followed by an "__=__" sign for assignment.  
+   The value (which is the assigment) comes write after the "__=__" sign. Please note that no quotes are required.
+   To mark the end of a pair definition a semicolon "__;__" is required.
+3. Every line in a __.kv__ file, which does not contain a "__=__" and a "__;__" sign, will be considered as a comment. Also, adding any text to a line after a semicolon has been set - to mark the end of a pair definition - will be ignored.