Final commit of gradling.

Played with the idea of putting the infos file in the jar, but then you
cannot write it (as a .jar is kinda like an exe) so it's better left
outside. Will be asking for merge now :)

README.md

 # Comptes
 Une appli CLI pour tenir des comptes entre un petit groupe de gens.
-Pour l'éxecuter, lancer `java -jar build/lib/MigrosCompteNG.jar`, ou tout simplement double cliquer sur le jar.
 
 ## IMPORTANT:
-NE PAS MODIFIER LE FICHIER `src/main/resources/infos` A LA MAIN!
+NE PAS MODIFIER LE FICHIER `infos` A LA MAIN!
 
-## Gradle 101:
+## User:
+Clone the repo, run:
+* Unix/Mac: `gradlew assemble`
+* Windows: `gradlew.bat assemble`
+The copy the `infos` file and the jar file in `build/libs/` to where you want to keep them. You can launch the application either through the command line using `java -jar <jarname>.jar` (with the same CWD as the `infos` file) or simply by double-clicking on the jar file.
+
+## Developer:
+Even though you can also work with the gradlew (gradle-wrapper) script, you'll probably want to install gradle. To build the project with the tests and static code analysis, run
+`gradle build` and then `gradle javadoc`. The above commands ofc also work for you.
+
+### Gradle 101:
 * build.gradle -- file configuring different taks. ≃ Makefile
 * gradle directory -- contains things proper to gradle. Don't touch.
 * gradlew -- script for poeple who don't have gradle installed, DL's a smaller version that enables them to do a reproducible build.
 * gradlew.bat -- same for idiots who run Windaube.
 * build dir -- output directory
 * src -- contains Main and Test, each with a java/ and resources/ directories. Source sets.
+Also, read the [docs](https://docs.gradle.org)!!