docs: more on README

Author: codinaut

README.md

@@ -1,12 +1,30 @@
 # envtestkit
 
-Test kit for logics with environment variable involvements.
-
 [![ci](https://github.com/codinaut/envtestkit/workflows/ci/badge.svg)](https://github.com/codinaut/envtestkit/actions?query=workflow%3Aci)
 [![crates.io](https://img.shields.io/crates/v/envtestkit.svg)](https://crates.io/crates/envtestkit)
 [![docs.rs](https://docs.rs/envtestkit/badge.svg)](https://docs.rs/envtestkit)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 
+Test kit for logics with environment variable involvements.
+
+## Usage
+
+See [the documentation](https://docs.rs/envtestkit).
+
+## Hacking
+
+This repository uses [semantic-release](https://github.com/semantic-release/semantic-release) for automated release and crate publishing. Please look at [Angular commit convention](https://github.com/conventional-changelog/conventional-changelog/tree/master/packages/conventional-changelog-angular).
+
+To test this crate:
+```sh
+cargo test
+```
+
+To see what's happening if environment tests aren't locked:
+```sh
+cargo test --examples -- --ignored
+```
+
 ## License
 
 [MIT](LICENSE).