Add Sphinx build config and more user docs, docstrings, type annotations, etc.

.gitignore

@@ -3,6 +3,9 @@
 pyrate_limiter.egg-info/
 __pycache__/
 dist/
+docs/_build/
+docs/modules/
+examples/
 htmlcov/
 env/
 test-reports/

.readthedocs.yml

@@ -0,0 +1,15 @@
+# Read the Docs configuration file
+version: 2
+
+sphinx:
+  builder: html
+  configuration: docs/conf.py
+
+python:
+  version: 3.8
+  system_packages: True
+  install:
+    - method: pip
+      path: .
+      extra_requirements:
+        - docs

CHANGELOG.md

@@ -4,7 +4,18 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
-## [2.7.0] - TBD
+## [2.8.1] - 2022-04-11
+### Added
+* Add Sphinx config
+* Add documentation site: https://pyrate-limiter.readthedocs.io
+* Add some missing type hints
+* Add package metadata to indicate PEP-561 compliance
+
+## [2.8.0] - 2022-04-10
+### Added
+* Add `flush()` method to all bucket classes
+
+## [2.7.0] - 2022-04-06
 ### Added
 * Add `FileLockSQliteBucket` for a SQLite backend with file-based locking
 * Add optional backend dependencies to package metadata

CONTRIBUTING.md

@@ -0,0 +1,37 @@
+# Contributing Guide
+Here are some basic instructions for local development setup and contributing to the project.
+
+## Setup & Commands
+To setup local development,  *Poetry* and *Python 3.6* is required. Python can be installed using *Pyenv* or normal installation from binary source. To install *poetry*, follow the official guideline (https://python-poetry.org/docs/#installation).
+
+Then, in the repository directory, run the following to install all optional backend dependencies and dev dependencies:
+```shell
+$ poetry install -E all
+```
+
+Some shortcuts are included for some common development tasks, using [nox](https://nox.thea.codes):
+- Run tests with: `nox -e test`
+- To run tests with coverage: `nox -e cover`
+- Format & check for lint error: `nox -e lint`
+- To run linting for every commit, run: `pre-commit install`
+
+## Documentation
+Documentation is generated using [Sphinx](https://www.sphinx-doc.org) and published on readthedocs.io.
+To build this documentation locally:
+```
+poetry install -E docs
+nox -e docs
+```
+
+## Guideline & Notes
+We have GitHub Action CICD to do the checking, testing and publishing work. So, there are few small notes when making Pull Request:
+- All existing tests must pass (Of course!)
+- Reduction in *Coverage* shall result in failure. (below 98% is not accepted)
+- When you are making bug fixes, or adding more features, remember to bump the version number in **pyproject.toml**. The number should follow *semantic-versioning* rules
+
+## TODO
+Planned features:
+* A rate limit may reset on a fixed schedule, eg: every first-day of a month
+* Sometimes, we may need to apply specific rate-limiting strategies based on schedules/region or some other metrics. It
+  requires the capability to switch the strategies instantly without re-deploying the whole service.
+  * Reference: https://www.keycdn.com/support/rate-limiting#types-of-rate-limits