Reorganize documentation & update Readme

docs/Development.md

@@ -0,0 +1,44 @@
+# Meritoo Common Library
+Development-related information
+
+# Getting started
+
+### Docker
+
+Build, create and start Docker's containers by running command:
+
+```bash
+docker-compose up -d
+```
+
+> [What is Docker?](https://www.docker.com/what-docker)
+
+### Composer
+
+Install packages by running command:
+
+```bash
+docker-compose run composer install
+```
+
+Update packages by running command:
+
+```bash
+docker-compose run composer update
+```
+
+### Tests
+
+Rebuild project and run tests by running command:
+
+```bash
+docker-compose exec php-cli phing
+```
+
+Run tests only by running command:
+
+```bash
+docker-compose exec php-cli phpunit
+```
+
+[‹ Back to `Readme`](../README.md)