CONTRIBUTION.md in duckdb-0.7.0 vs CONTRIBUTION.md in duckdb-0.7.1

@@ -1,24 +1,45 @@
 # Contribution Guide
 
+## Environment setup
+
+### With docker
+
+1. Fork the repository and `git clone` to your local machine.
+2. Build and access to docker container
+
+```
+docker-compose build ubuntu
+docker-compose run --rm ubuntu bash
+```
+
+In case you want custom ruby or duckdb versions, use `--build-arg` options
+```
+docker-compose build ubuntu --build-arg RUBY_VERSION=3.1.3 --build-arg DUCKDB_VERSION=0.6.0
+```
+
+### Without docker
+
+1. Install [Ruby](https://www.ruby-lang.org/) into your local machine.
+2. Install [duckdb](https://duckdb.org/) into your local machine.
+3. Fork the repository and `git clone` to your local machine.
+4. Run `bundle install`
+5. Run `rake build`
+   or you might run with C duckdb header and library directories:
+   `rake build -- --with-duckdb-include=/duckdb_header_directory --with-duckdb-lib=/duckdb_library_directory`
+
+
 ## Issue
 
 If you spot a problem, [search if an issue already exists](https://github.com/suketa/ruby-duckdb/issues).
 If a related issue doesn't exist, you can open a [new issue](https://github.com/suketa/ruby-duckdb/issues/new).
 
 
 ## Fix Issues or Add New Features.
 
-1. install [Ruby](https://www.ruby-lang.org/) into your local machine.
-2. install [duckdb](https://duckdb.org/) into your local machine.
-3. fork the repository and `git clone` to your local machine.
-4. run `bundle install`
-5. run `rake build`
-   or you might run with C duckdb header and library directories:
-   `rake build -- --with-duckdb-include=/duckdb_header_directory --with-duckdb-lib=/duckdb_library_directory`
-6. run `rake test`
-7. create new branch to change the code.
-8. change the code.
-9. write test.
-10. run `rake test` and confirm all tests pass.
-11. git push.
-12. create PR.
+1. Run `rake test`
+2. Create new branch to change the code.
+3. Change the code.
+4. Write test.
+5. Run `rake test` and confirm all tests pass.
+6. Git push.
+7. Create PR.