Add synopsis and description

dolmen.opam

@@ -1,20 +1,32 @@
-opam-version: "1.2"
+opam-version: "2.0"
 name: "dolmen"
 version: "0.4"
-author: "Guillaume Bury"
 maintainer: "[email protected]"
 license: "BSD-2-clauses"
 build: [
   ["dune" "subst"] {pinned}
   ["dune" "build" "-p" name "-j" jobs]
 ]
 depends: [
+  "ocaml" {>= "4.02.3"}
   "menhir" {>= "20151005"}
   "dune" {build}
 ]
-available: [ ocaml-version >= "4.02.3" ]
 tags: [ "parser" "tptp" "logic" "smtlib" "dimacs" ]
 homepage: "https://github.com/Gbury/dolmen"
 doc: "http://gbury.github.io/dolmen"
 bug-reports: "https://github.com/Gbury/dolmen/issues"
-dev-repo: "https://github.com/Gbury/dolmen.git"
+dev-repo: "git+https://github.com/Gbury/dolmen.git"
+authors: "Guillaume Bury"
+synopsis: "A parser library"
+description:
+"Dolmen is a parser library. It currently targets languages used in automated theorem provers,
+but may be extended ot other domains.
+
+Dolmen provides functors that takes as arguments a representation of terms and statements,
+and returns a module that can parse files (or streams of tokens) into the provided representation
+of terms or statements. This is meant so that Dolmen can be used as a drop-in replacement of existing
+parser, in order to factorize parsers among projects.
+
+Additionally, Dolmen also provides a standard implementation of terms and statements that cna be
+used ot instantiate its parsers."