update contributing.md (#54)

* update contributing.md

* update doc

CONTRIBUTING.md

@@ -1,16 +1,25 @@
-# Publishment flow
+# For Maintainer
 
-## Rust
+## Publishing flow
 
+Testing and publishing are automatically done in GitHub Actions.
+The definitions are located under `.github` directory.
+
+### Rust
+
+1. Get a token from crates.io and set it into `CRATES_PASS` secrets via the settings page of this repository
+    - Token can be issued in "API Access" section in [crates.io account settings page](https://crates.io/me)
 1. Fix version in `Cargo.toml` (e.g. 0.1.0)
-1. Git tag version with prefix `rust/` (e.g. `git tag rust/0.1.0)
+1. Git tag version with prefix `rust/` (e.g. `git tag rust/0.1.0`)
 1. Push tag to master
-1. CI automatically publish crates to crates.io after testing
+1. CI automatically publish a new crate to crates.io after testing
 
-## Python
+### Python
 
+1. Set the PyPi user name and password into `PYPI_USER` and `PYPI_PASS` respectively, via the settings page of this repository.
 1. Fix version in `python/pyproject.toml`, `python/Cargo.toml`, `python/src/lib.rs`
-    - Easily done with [pyversionup](https://github.com/tamuhey/pyversionup): `versionup 0.1.0`
+    - Easily done with [pyversionup](https://github.com/tamuhey/pyversionup): e.g. `versionup 0.1.0`
 1. Git tag version with prefix `python/`
 1. Push tag to master
-1. CI automatically publish package to pypi after testing
+1. CI automatically publish package to PyPi after testing
+