Add README (#3)

README.md

@@ -0,0 +1,79 @@
+# Compact Encoding Detection for Ruby
+
+Ruby bindings for [Google's Compact Encoding Detection](https://github.com/google/compact_enc_det) (CED for short) C++ library
+
+## Usage
+
+You will need [CMake](https://cmake.org) to build the C++ native extension.
+
+>  macOS
+> 
+> You can use [Homebrew](https://brew.sh) to install it:
+> 
+> ```console
+> brew install cmake
+> ```
+
+Then you can install the gem from [RubyGems.org](https://rubygems.org/gems/compact_enc_det).
+
+> Either add this to your Gemfile:
+>
+> ```ruby
+> gem 'compact_enc_det', '~> 0.1'
+> ```
+> or run the following command to install it:
+>
+> ```console
+> gem install compact_enc_det
+> ```
+
+Now you can detect the encoding via the `CompactEncDet.detect_encoding`,
+which is a thin wrapper around `CompactEncDet::DetectEncoding` and `MimeEncodingName` functions from the C++ library.
+
+> ```ruby
+> file = File.read("unknown-encoding.txt")
+> result = CompactEncDet.detect_encoding(file, file.bytesize)
+> result.encoding
+> # => #<Encoding:Windows-1250>
+> result.bytes_consumed
+> # => 239
+> result.is_reliable?
+> # => true
+> ```
+
+## Contributing
+
+Any contributions are welcome! Feel free to open an issue or a pull request.
+
+### Repository
+
+The [google/compact_enc_det](https://github.com/google/compact_enc_det) repository is linked as a Git submodule at `ext/compact_enc_det/compact_enc_det`.
+
+> You need to clone the repository with `--recurse-submodules` flag:
+> 
+> ```console
+> git clone --recurse-submodules [email protected]:cloudaper/compact_enc_det.git
+> ```
+> 
+> Or initialize and update the submodule after cloning with the following commands:
+> 
+> ```console
+> git submodule init && git submodule update
+> ```
+
+### Testing
+
+Tests located at `tests` use the [minitest](https://github.com/minitest/minitest) framework.
+
+> Run the tests via test Rake task:
+> 
+> ```console
+> rake test
+> ```
+> 
+> The gem will be compiled to `lib/compact_enc_det/compact_enc_det.bundle` first.
+
+## License
+
+This gem is released under [MIT license](LICENSE), while the original Google's [Compact Encoding Detection library](https://github.com/google/compact_enc_det) source code,
+located at `ext/compact_enc_det/compact_enc_det`, is under the [Apache-2.0](LICENSE-APACHE) license.

compact_enc_det.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.licenses = ["MIT", "Apache-2.0"]
 
   spec.extensions = ["ext/compact_enc_det/extconf.rb"]
-  spec.files = Dir["ext/**/*", "lib/**/*"]
+  spec.files = Dir["ext/**/*", "lib/**/*", "README.md", "LICENSE", "LICENSE-APACHE"]
 
   spec.require_paths = ["lib"]