Fixes #201

* create HowTo.md documentation for users

* syntaxe fixes and add Todsl part

* some corrections, delete useless parts, sentence form etc...

HowTo.md

@@ -0,0 +1,76 @@
+<h1 align="center">How to Aadarchi ?</h1>
+
+
+## Install
+
+To add Aadarchi plugin to your project you need to add it to your pom.xml.<br>
+You can copy and paste this in your build's plugins section :
+
+```xml
+<plugin>
+    <groupId>io.github.Riduidel.aadarchi</groupId>
+    <artifactId>aadarchi-maven-plugin</artifactId>
+    <version>0.1.1</version>
+    <executions>
+        <execution>
+            <goals>
+                <goal>generate-model</goal>
+            </goals>
+        </execution>
+    </executions>
+</plugin>
+```
+
+Don't forget to replace the value of `version` maven property by ![GitHub version](https://badge.fury.io/gh/Riduidel%2Faadarchi.svg)
+
+## Usage
+
+Aadarchi needs a description of your architecture, which is usually done in a workspace.dsl file (but can also be done in pure Java code).
+
+This file is an architecture description of your project in structurizr's domain-specific language. To learn more about how this DSL works, you can find all usefull informations there :
+[workspace.dsl language reference](https://github.com/structurizr/dsl/blob/master/docs/language-reference.md)
+
+This "workspace.dsl" should be located in `src/architecture/resources/` (we will see later how to change this default path).
+
+If you want, you can use this empty template :
+
+```java
+workspace {
+
+        model {
+            user = person "User" "A user of my software system."
+            softwareSystem = softwareSystem "Software System" "My software system."
+
+            user -> softwareSystem "Uses"
+        }
+
+        views {
+            systemContext softwareSystem "SystemContext" {
+                include *
+                autoLayout
+            }
+
+            styles {
+                element "Software System" {
+                    background #1168bd
+                    color #ffffff
+                }
+                element "Person" {
+                    shape person
+                    background #08427b
+                    color #ffffff
+                }
+            }
+        }
+
+}
+```
+You should now be able to run `mvn install` to build your project and use Aadarchi. 
+
+If the build success, it should have created a "structurizr" file in `target/`
+
+## Go further
+
+### ConfigProperties
+
+Some properties can be modified ... where ? how ? only god knows...