Move documentation to doc directory (#84)

Author: kazuhitoyokoi

README.md

@@ -1,6 +1,6 @@
 # Node generator for Node-RED
 
-Node generator is command line tool to generate Node-RED node modules from a number of different sources including Swagger specification and function node's source.
+Node generator is command line tool to generate Node-RED node modules from several various sources including Swagger specification and function node's source.
 Using this tool, node developers can dramatically reduce their time to implement Node-RED node modules.
 
 ## Installation
@@ -34,28 +34,34 @@ You may need to run this with `sudo`, or from within an Administrator command sh
        --tgz : Save node as tgz file
        --help : Show help
 
-### Example 1. Create original node from function node (JavaScript code)
+### Example 1. Create original node from Swagger definition
 
-- On Node-RED flow editor, save function node to library with file name (lower-case.js).
-- node-red-nodegen ~/.node-red/lib/function/lower-case.js
-- cd node-red-contrib-lower-case
+- node-red-nodegen http://petstore.swagger.io/v2/swagger.json
+- cd node-red-contrib-swagger-petstore
 - sudo npm link
 - cd ~/.node-red
-- npm link node-red-contrib-lower-case
+- npm link node-red-contrib-swagger-petstore
 - node-red
 
--> You can use lower-case node on Node-RED flow editor.
+-> You can use swagger-petstore node on Node-RED flow editor.
 
-### Example 2. Create original node from Swagger definition
+### Example 2. Create original node from function node (JavaScript code)
 
-- node-red-nodegen http://petstore.swagger.io/v2/swagger.json
-- cd node-red-contrib-swagger-petstore
+- On Node-RED flow editor, save function node to library with file name (lower-case.js).
+- node-red-nodegen ~/.node-red/lib/function/lower-case.js
+- cd node-red-contrib-lower-case
 - sudo npm link
 - cd ~/.node-red
-- npm link node-red-contrib-swagger-petstore
+- npm link node-red-contrib-lower-case
 - node-red
 
--> You can use swagger-petstore node on Node-RED flow editor.
+-> You can use lower-case node on Node-RED flow editor.
 
-Note: Currently node generator supports GET and POST methods using JSON format without authentication.
+## Documentation
+- [Use cases](docs/index.md#use-cases) ([Japanese](docs/index_ja.md#use-cases))
+- [How to use Node generator](docs/index.md#how-to-use-node-generator) ([Japanese](docs/index_ja.md#how-to-use-node-generator))
+- [Generated files which node package contains](docs/index.md#generated-files-which-node-package-contains) ([Japanese](docs/index_ja.md#generated-files-which-node-package-contains))
+- [How to create node from Swagger definition](docs/index.md#how-to-create-node-from-swagger-definition) ([Japanese](docs/index_ja.md#how-to-create-node-from-swagger-definition))
+- [How to create node from function node](docs/index.md#how-to-create-node-from-function-node) ([Japanese](docs/index_ja.md#how-to-create-node-from-function-node))
 
+Note: Currently node generator supports GET and POST methods using JSON format without authentication.