documentation, new methods, new capi version

Author: osch

README.md

@@ -10,6 +10,8 @@ This [Lua] module provides an array data type and the implementation of the [Car
 for handling arrays of primitive numeric C data types in Lua script code and also in native 
 C code for enhancing native Lua module interoperability and performance. 
 
+   * [Documentation](./doc/README.md#lua-carray-documentation)
+
 [Lua]:          https://www.lua.org
 [Carray C API]: https://github.com/lua-capis/lua-carray-capi
 
@@ -18,7 +20,7 @@ C code for enhancing native Lua module interoperability and performance.
 ## First Example
 
  ```lua
-local carray = require"carray"
+local carray = require("carray")
 
 local a = carray.new("int", 10)
 
@@ -52,15 +54,14 @@ assert(x == 202)
 assert(y == 203)
 assert(z == 204)
 
-local c = carray.new("char", 10)
-c:setstring(1, "1234567890")
+local c = carray.new("char"):add("1234567890")
 
 assert(c:get(1) == string.byte("1"))
 assert(c:tostring() == "1234567890")
-assert(c:tostring(1) == "1")
+assert(c:tostring(1,1) == "1")
 assert(c:tostring(2,4) == "234")
 
-c:setstring(4, "abc")
+c:set(4, "ab", string.byte("c"))
 assert(c:tostring() == "123abc7890")
 ```