Add usage instructions for Eclipse users (#290)

Many will opt for simply copying the lib to the libs folder, but this
allows building the API project as necessary, while maintaining an
updated version of the lib produced in the target project.
** Intended for only building the target project with Eclipse **

Author: TwistedUmbrella

README.md

@@ -35,6 +35,8 @@ ___
 # Usage
 You can import the lib directly from the jar OR with Maven/Gradle/SBT/Leiningen using JitPack : [![](https://jitpack.io/v/Grover-c13/PokeGOAPI-Java.svg)](https://jitpack.io/#Grover-c13/PokeGOAPI-Java)
 
+  PS : To Eclipse user, add the generated jar into the eclipse build path : Right click on the project > Build path > Java Build Path > Select Libraries tab > Add External JARs… > Select `PokeGOAPI-Java/build/libs/PokeGOAPI-Java_bundle-0.0.1-SNAPSHOT.jar` > Finish
+
 Mostly everything is accessed through the PokemonGo class in the API package.
 The constructor of PokemonGo class requires a CredentialsProvider object (which can be obtained from GoogleCredentialsProvider or PtcCredentialsProvider) and a OkHttpClient object.