Resolve "complete mini project 2"

Closes #7 (closed)

project2/README.md

+# Mini project 2
+
+This project includes: 
+
+- an 3 jobs 3 machines instance of job-shop in Prolog: `jobshop3.pl`
+- a model of this instance in Z3: `jobshop3.smt2`
+- a model of the 10 jobs 5 machines instance in the same format as `https://github.com/tamy0612/JSPLIB/blob/master/instances/la05`: `jobshop10-5`
+
+### Usage 
+Prolog and Z3 are done online on `https://swish.swi-prolog.org/` and `https://compsys-tools.ens-lyon.fr/z3/` respectively.