docs: update readme file

Author: paodb

README.md

@@ -18,6 +18,28 @@ Vaadin 14+ addon for Google Maps Web Component
 
 [Available in Vaadin Directory](https://vaadin.com/directory/component/google-maps-addon)
 
+### Maven install
+
+Add the following dependencies in your pom.xml file:
+
+```xml
+<dependency>
+   <groupId>com.flowingcode.vaadin.addons</groupId>
+   <artifactId>google-maps</artifactId>
+   <version>X.Y.Z</version>
+</dependency>
+```
+<!-- the above dependency should be updated with latest released version information -->
+
+```xml
+<repository>
+   <id>vaadin-addons</id>
+   <url>https://maven.vaadin.com/vaadin-addons</url>
+</repository>
+```
+
+For SNAPSHOT versions see [here](https://maven.flowingcode.com/snapshots/).
+
 ## Building and running demo
 
 - git clone repository
@@ -35,14 +57,18 @@ The issues for this add-on are tracked on its github.com page. All bug reports a
 
 ## Contributions
 
-Contributions are welcome, but there are no guarantees that they are accepted as such. Process for contributing is the following:
+Contributions are welcome, but there are no guarantees that they are accepted as such. 
 
-- Fork this project
+As first step, please refer to our [Development Conventions](https://github.com/FlowingCode/DevelopmentConventions) page to find information about Conventional Commits & Code Style requeriments.
+
+Then, follow these steps for creating a contibution:
+
+- Fork this project.
 - Create an issue to this project about the contribution (bug or feature) if there is no such issue about it already. Try to keep the scope minimal.
 - Develop and test the fix or functionality carefully. Only include minimum amount of code needed to fix the issue.
-- Refer to the fixed issue in commit
-- Send a pull request for the original project
-- Comment on the original issue that you have implemented a fix for it
+- For commit message, use [Conventional Commits](https://github.com/FlowingCode/DevelopmentConventions/blob/main/conventional-commits.md) to describe your change.
+- Send a pull request for the original project.
+- Comment on the original issue that you have implemented a fix for it.
 
 ## License & Author
 
@@ -55,14 +81,24 @@ GoogleMapsAddon is written by Flowing Code S.A.
 ## Getting started
 
 Create an instance of GoogleMap, configure it, add markers, polygons, etc:
+```java
+GoogleMap gmaps = new GoogleMap(apiKey,null,null);
+gmaps.setMapType(MapType.SATELLITE);
+gmaps.setSizeFull();
+gmaps.setCenter(new LatLon(0,0));
+gmaps.addMarker("Center", new LatLon(0,0), true, "");
+GoogleMapPolygon gmp = gmaps.addPolygon(Arrays.asList(new GoogleMapPoint(gmaps.getCenter()),
+new GoogleMapPoint(gmaps.getCenter().getLat(),gmaps.getCenter().getLon()+1),
+new GoogleMapPoint(gmaps.getCenter().getLat()+1,gmaps.getCenter().getLon())));
+gmp.addClickListener(ev->Notification.show("polygon clicked"));
 ```
-            GoogleMap gmaps = new GoogleMap(apiKey,null,null);
-            gmaps.setMapType(MapType.SATELLITE);
-            gmaps.setSizeFull();
-            gmaps.setCenter(new LatLon(0,0));
-            gmaps.addMarker("Center", new LatLon(0,0), true, "");
-            GoogleMapPolygon gmp = gmaps.addPolygon(Arrays.asList(new GoogleMapPoint(gmaps.getCenter()),
-            new GoogleMapPoint(gmaps.getCenter().getLat(),gmaps.getCenter().getLon()+1),
-            new GoogleMapPoint(gmaps.getCenter().getLat()+1,gmaps.getCenter().getLon())));
-            gmp.addClickListener(ev->Notification.show("polygon clicked"));
-```
+
+## Special configuration when using Spring
+
+By default, Vaadin Flow only includes ```com/vaadin/flow/component``` to be always scanned for UI components and views. For this reason, the addon might need to be whitelisted in order to display correctly. 
+
+To do so, just add ```com.flowingcode``` to the ```vaadin.whitelisted-packages``` property in ```src/main/resources/application.properties```, like:
+
+```vaadin.whitelisted-packages = com.vaadin,org.vaadin,dev.hilla,com.flowingcode```
+ 
+More information on Spring whitelisted configuration [here](https://vaadin.com/docs/latest/integrations/spring/configuration/#configure-the-scanning-of-packages).