glop: Update README.md

Author: Mizux

ortools/glop/README.md

@@ -1,7 +1,28 @@
-# Glop
+# GLOP
 
-Glop is Google's Linear Optimization Package. It provides a fast,
-precise, numerically stable, production-ready system for linear programming.
+GLOP is Google's Linear Optimization Package. It is a full-featured,
+production-ready implementation of the revised simplex method designed for
+performance and numerical stability in solving linear programming problems.
 
 It's written in C++ but can also be used from Java, Python, or C# via our
 [linear solver wrapper](../linear_solver).
+
+It contains in particular:
+
+* [`parameters.proto`][parameters_proto]: Contains the definitions for all the
+  GLOP algorithm parameters and their default values.
+* [`lp_solver.h`][lp_solver_h]: Contains the primary entry point class
+  `LPSolver`.
+* [`preprocessor.h`][preprocessor_h]: Contains the presolving code for a
+  Linear Program.
+* [`revised_simplex.h`][revised_simplex_h]: Contains the core implementation of
+  the revised simplex algorithm as described by G.B. Dantzig.
+* [`status.h`][status_h]: Return type for various solver functions.
+
+<!-- Links used throughout the document. -->
+[parameters_proto]: ../glop/parameters.proto
+[benchmark_proto]: ../glop/benchmark.proto
+[lp_solver_h]: ../glop/lp_solver.h
+[preprocessor_h]: ../glop/preprocessor.h
+[revised_simplex_h]: ../glop/revised_simplex.h
+[status_h]: ../glop/status.h