APP-3082 Architecture Overview (finos#258)

* APP-3082 SVG Rendering in Markdown test

* APP-3082 Updated diagram

* APP-3082 Removed unused Jersey dependency

* APP-3082 WIP

* APP-3110 arch doc

* APP-3110 removed unused javax.ws.rs.core.GenericType import from ApiException class

* APP-3082 fixes

* APP-3082 Link to Architecture Presentation from ./docs/index.md

CONTRIBUTING.md

@@ -17,7 +17,7 @@ New feature requests on the legacy SDK will not be accepted.
 This repository contains both the legacy Java SDK under the [symphony-bdk-legacy module](symphony-bdk-legacy) 
 and the BDK2.0 under all other root modules.
 Please check the [legacy module readme file](symphony-bdk-legacy/README.md) and the 
-[BDK2.0 architecture file](docs/internal/bdk-architecture.md) for more information.
+[BDK architecture](docs/tech/architecture.md) documentation for more information.
 
 ## Testing
 

docs/index.md

@@ -21,3 +21,5 @@ The reference documentation consists of the following sections:
 Getting Started guides are also available for Spring Boot:
 - [Core Starter](./spring-boot/core-starter.md)
 
+### Technical Documentation
+You can find an overview of the BDK Architecture [here](./tech/architecture.md).

docs/spring-boot/core-starter.md

@@ -252,3 +252,6 @@ public class GifFormActivity extends FormReplyActivity<FormReplyContext> {
   }
 }
 ```
+
+----
+[Home :house:](../index.md)

docs/tech/architecture.md

@@ -0,0 +1,46 @@
+# BDK Architecture Presentation
+The Symphony BDK for Java is a multi-module library that uses [Gradle](https://gradle.org/) as build system. 
+This page will help to clearly understand how the library has been designed. This can be also useful for new contributors
+aiming to provide additional features or implementations or existing APIs. 
+
+## Architecture Overview
+The following diagram aims to give an overview of the different layers and modules provided by the BDK library.
+![Architecture Overview Diagram](architecture.svg)
+
+### symphony-bdk-core
+The `symphony-bdk-core` is the main module that allows developers to write bots from a pure Java main application. It contains
+all necessary BDK features such as: 
+- [configuration](../configuration.md) 
+- [authentication](../authentication.md)
+- [datafeed](../datafeed.md)
+- [services](../message.md)
+- [activity API](../activity-api.md)
+
+#### Code Generation
+The `symphony-bdk-core` module relies on the [openapi-generator-maven-plugin](https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator-maven-plugin/README.md)
+to generate API clients and models from official Symphony's [Swagger specifications](https://github.com/symphonyoss/symphony-api-spec).
+API's clients are located under package `com.symphony.bdk.gen.api` and models under `com.symphony.bdk.gen.api.model`.
+
+### symphony-bdk-http
+The `symphony-bdk-http-api` module defines a generic interface for performing HTTP calls. Along with this interface, it
+also provides a utility `com.symphony.bdk.http.api.HttpClient` class helping developers to perform calls to external systems.
+> :warning: It is important to notice that interface `com.symphony.bdk.http.api.ApiClient` is used by generated code. 
+> Changing contract would break the build. See [Code Generation](#code-generation).
+
+At the moment, two different implementations have been created for the `com.symphony.bdk.http.api.ApiClient` interface:
+- `com.symphony.bdk.http.jersey2.ApiClientJersey2` contained in module `symphony-bdk-http-jersey2` (default implementation for [Core](#symphony-bdk-core))
+- `com.symphony.bdk.http.webclient.ApiClientWebClient` contained in module `symphony-bdk-http-webclient` (default implementation for [Spring Boot](#symphony-bdk-spring))  
+
+### symphony-bdk-template
+The `symphony-bdk-template-api` module defines a set of interfaces that allows developers to load and fill text files with 
+data. This API is especially useful for complex MessageML templating.
+
+At the moment, two different module implementations have been created: 
+- `symphony-bdk-template-freemarker`
+- `symphony-bdk-template-handlebars`
+
+### symphony-bdk-spring
+The Symphony BDK comes also with two _starter_ modules to ease integration with the Spring Boot framework: 
+- `symphony-bdk-core-spring-boot-starter` that is basically a wrapper around the [symphony-bdk-core](#symphony-bdk-core) module
+- `symphony-bdk-app-spring-boot-starter` that is a foundation for [Extension Applications](https://developers.symphony.com/symphony-developer/docs/overview-of-extension-applications) 
+backend development

symphony-bdk-http/symphony-bdk-http-api/build.gradle

@@ -1,10 +1,10 @@
 description = 'Symphony Java BDK Core Http API'
 
 dependencies {
+
     compileOnly 'org.projectlombok:lombok'
     annotationProcessor 'org.projectlombok:lombok'
 
     implementation 'org.apiguardian:apiguardian-api'
-    implementation 'org.glassfish.jersey.core:jersey-client'
 }
 

symphony-bdk-http/symphony-bdk-http-api/src/main/java/com/symphony/bdk/http/api/ApiException.java

@@ -1,16 +1,16 @@
 package com.symphony.bdk.http.api;
 
+import com.symphony.bdk.http.api.util.TypeReference;
+
 import lombok.Getter;
 import org.apiguardian.api.API;
 
 import java.net.HttpURLConnection;
 import java.util.List;
 import java.util.Map;
 
-import javax.ws.rs.core.GenericType;
-
 /**
- * Main exception raised when invoking {@link ApiClient#invokeAPI(String, String, List, Object, Map, Map, Map, String, String, String[], GenericType)}.
+ * Main exception raised when invoking {@link ApiClient#invokeAPI(String, String, List, Object, Map, Map, Map, String, String, String[], TypeReference)}.
  *
  * Initially generated by the OpenAPI Maven Generator
  */

symphony-bdk-http/symphony-bdk-http-api/src/main/java/com/symphony/bdk/http/api/package-info.java

@@ -0,0 +1,9 @@
+/**
+ * This module provides contract for performing HTTP calls.
+ *
+ * <p>
+ *   <b>WARNING</b>: The interface {@link com.symphony.bdk.http.api.ApiClient} is used by generated code.
+ *   Changing the contract will break code generation.
+ * </p>
+ */
+package com.symphony.bdk.http.api;