update README

README.markdown

@@ -1,7 +1,29 @@
 # eregex.vim
 
+## Installation
+
+Vimball package will not release until english doc is ready.
+Now you can clone this repo and use [vim-makefile][] to install.
+
+[vim-makefile]:http://github.com/c9s/vim-makefile
+
+## Usage
+
+Add the following three lines to your vimrc file.
+
+    nnoremap / :M/
+    nnoremap ? :M?
+    nnoremap ,/ /
+
+Now you can use / to find. :%S// (uppercase S) to replace.
+
+===============================================================
+## License
+
 Author     : 安久津  
 Origin     : [eregex.vim][origin]  
 Maintainer : othree  
 
+Might release under MIT License.
+
 [origin]:http://www.vector.co.jp/soft/unix/writing/se265654.html