Update README.md

Author: kojix2

README.md

@@ -1,7 +1,17 @@
-# samtools-mruby
+# bcftools-mruby
 
 [![build](https://github.com/kojix2/bcftools-tanuki/actions/workflows/build.yml/badge.svg)](https://github.com/kojix2/bcftools-tanuki/actions/workflows/build.yml)
 
+Use [mruby](https://github.com/mruby/mruby) to evaluate expressions.
+
+## Installation
+
+```
+git clone --recurse-submodules https://github.com/kojix2/bcftools-mruby
+./build.sh
+bcftools/bcftools tanuki # check if it works
+```
+
 ```
 　　　　__,-─-､__
 　　　（〆-─-ヽ)
@@ -13,6 +23,26 @@
  tanuki in bcftools
 ```
 
+[Rake](https://github.com/ruby/rake) is required to build mruby.
+If you are using [conda to install Ruby](https://dev.to/kojix2/using-ruby-with-conda-1hn), setting the `LD` environment may work.
+
+```sh
+rake LD=/usr/bin/gcc MRUBY_CONFIG=$(pwd)/mruby_build_config.rb -f $(pwd)/mruby/Rakefile
 ```
-./build.sh
-```
+
+## Usage
+
+## Development
+
+## Contributing
+
+- Fork it
+- Pull Request welcome
+
+## License
+
+MIT
+
+## Related Projects
+
+- [samtools-mruby](https://github.com/kojix2/samtools-mruby)