Add documentation index

README.md

@@ -6,6 +6,9 @@
 
 This repository contains sources for all packages from `yokai/batch` suite.
 
+## Documentation
+
+You should start with [centralized documentation](https://github.com/yokai-php/batch-src/blob/0.x/docs/README.md).
 
 ## Packages
 
@@ -30,12 +33,6 @@ And some special packages :
 - [`yokai/batch-symfony-pack`](https://github.com/yokai-php/batch-symfony-pack): Minimal pack for Symfony Framework
 
 
-## Documentation
-
-Every package has its own documentation,
-you should start with [core repository documentation](https://github.com/yokai-php/batch/blob/0.x/README.md).
-
-
 ## Contribution
 
 Please feel free to open an [issue](https://github.com/yokai-php/batch-src/issues)

docs/README.md

@@ -0,0 +1,64 @@
+## Installation
+
+```bash
+composer require yokai/batch
+```
+
+## What is Batch ?
+The Batch library solves all your massive data processing problems.
+
+Batch can also be used as an ETL.
+
+Batch can also work asynchronously.
+
+Batch help you to make reporting during process.
+
+## How it works ?
+Batch is a library that allows you to declare and execute jobs.
+And having control over each step of the process to be able to extend the technical logic to meet business needs.
+
+## Vocabulary
+
+Because when you start with any library
+it is important to understand what are the concepts introduced in it.
+
+This is highly recommended that you read this entire page
+before starting to work with this library.
+
+### Job
+A job is the class that is responsible for **what** your code is doing.
+
+This is the class you will have to create (or reuse),
+as it contains the business logic required for what you wish to achieve.
+
+The only requirement is implementing [`JobInterface`](../src/batch/src/Job/JobInterface.php),
+
+#### See More:
+For more information about jobs, see [Job](batch/domain/job.md)
+
+### Job Launcher
+
+The job launcher is responsible for executing/scheduling every jobs.
+
+Yeah, executing OR scheduling. There is multiple implementation of a job launcher across bridges.
+Job's execution might be asynchronous, and thus, when you ask the job launcher to "launch" a job,
+you have to check the `JobExecution` status that it had returned to know if the job is already executed.
+
+#### What is needed to use a Job Launcher ?
+
+For use a Job Launcher you need to have:
+- **A Container of Jobs:** A container use any PSR-11 [container implementation](https://packagist.org/providers/psr/container-implementation)
+- **A Storage for Job Executions:** A storage to store the execution of jobs, it can be a database, a file, a cache, etc.
+- **A JobExecutor:** The executor will execute the job.
+- **A JobExecutionAccessor:** The accessor will access the job execution.
+
+### JobExecution:
+
+A [JobExecution](../src/batch/src/JobExecution.php) is the class that holds information about one execution of a job.
+
+### JobExecutionStorage
+
+Whenever a job is launched, whether is starts immediately or not, an execution is stored for it.
+The execution are stored to allow you to keep an eye on what is happening.
+This persistence is on the responsibility of the job execution storage.
+- [Job Execution Storage](batch/domain/job-execution-storage.md)