README: Move to markdown

I'm working on the cangjians.github.io website, and I'm using markdown
for it.

Moving this file to markdown allows me to reuse it as a page in the
website, without nay modification, which is quite nice.
README: Point to the online documentation
README: Drop the mention to the INSTALL.rst page

It's so obvious that the installation instructions are in the file named
INSTALL...
README: Drop the mention to the AUTHORS file

People are telling me that they don't find the AUTHORS file in the Git
tree, which is normal as it's generated when creating the tarball. I can
understand it is confusing, though.

It's also becoming problematic when we reuse the README as a page of the
website.

All in all, let's remove it and avoid the confusion.
README: Fix extension

Apparently the extension must be .md, I thought Github would consider
extension-less README files as Markdown by default. :(
INSTALL: Move to markdown

Just like the README, this will be reused on the website to provide the
installation instructions.
Merge pull request #2 from yookoala/master

Fixed code issue with U+9ec3 and U+9ec4
docs: Document the API

This is a first pass, which should already be pretty good, but we'll
make it better with user feedback.

It's in Markdown, so that we can reuse it as it is on the website, with
as few changes as possible.
docs: Remove the Jekyll front matters

These are only necessary on the website, and they would probably confuse
readers of the documentation from the source distribution.
Be C89 friendly, declare variables on the top of the functions
Merge pull request #6 from linquize/c89

C89
Add UTF-8 BOM in source files where Chinese characters are directly embedded in
Use strtok_s instead of strtok_r for MSVC
use sprintf_s instead of sprintf for MSVC
Merge pull request #7 from linquize/msvc

Make it compile with MSVC
Remove const of char** variable in API signature

Initial problem was on pycangjie2 library, in order to downgrade cython
required version from 0.17 to 0.14 (default version of  Ubuntu 12.04
    LTS), we needed to remove const attribute in signature. In cangjie_get_radical function, signature of radical was const char**, we changed it to char** and modify body of the function to comply with that.
Be C89 friendly, declare variables on the top of the functions
Merge pull request #8 from Chwing/master

Remove const of char** variable in API signature
Merge pull request #9 from linquize/c89

Be C89 friendly, declare variables on the top of the functions
Use _putenv instead of setenv on MSVC