add Readme.md

Readme.md

+## About
+The purpose of this Gadget is export of a git repositories which contain web projects
+into ERP5 bt5 format. ERP5 allows to upload this format as business template.    
+## TODO
+1. currently zip is used as exported format, but erp5 bt5 tgz is needed. So repack is needed after export.
+1. deploy jekill hosting pages to lab.nexedi.com .
+## Using
+to use this Gadget the following steps should be done:
+ 1. fork current repository and add `names of exported respositories` in index.html
+ 1. public current repository to GitHub Pages hosting `you can find it in repository settings`
+ 1. create index template in exported repository [erp5_/index.appcache](erp5_/index.appcache)
+ 1. create config in exported repository `erp5_/erp5.json` 
+ 1. public repository branch containing the above files to GitHub Pages.
+ 1. add repository name to index.html
+ 1. open gadget page then select repo and press button export
+##erp5_/erp5.json example:
+```json
+{
+  "name": "erp5_officejs_fs2erp5_gadget",
+  "description": "RenderJs gadget allows to export github published repos as bt for import repos into erp5.",
+  "version": "001",
+  "authors": [
+    "Copyright (c) 2017 Nexedi SA"
+  ],
+  "license": "LGPL3",
+  "excluded_paths": [
+    "build/"
+  ],
+  "dependencies": [
+    "erp5_officejs_onlyoffice_fonts"
+  ],
+  "scopes": [
+    {
+      "prefix": "onlyoffice/",
+      "paths": [
+        "apps/css.js",
+        "apps/documenteditor/main/app/"
+      ]
+    },
+    {
+      "prefix": "onlyoffice/",
+      "delete_path_part": "deploy/web-apps/",
+      "paths" : [
+        "deploy/web-apps/apps/common/main/resources/"
+      ],
+      "excluded_paths": [
+        "deploy/web-apps/apps/common/main/resources/img/"
+      ]
+    }
+  ]
+}
+```
+### name
+the name of created bt5 package 
+### dependecies
+used to generate erp5 bt5 dependency_list
+### id_prefix
+if used then id_prefix added to erp5 id of every exported document.
+id_prefix will not be added to the path of the document.
+id_prefix may be used for different documents having the same path can relate to different erp5 business templates.     
+### scopes
+if option scopes used when only files in scope.paths are used for creating erp5 package.
+### scopes.prefix
+prefix which will be added to the path (reference) of the document in erp5