prepare release (v2.0) (ocaml-community#72)

* add description in opam file
* link to API documentation from README (addresses ocaml-community#67)
* update version number to 2.0

Author: smolkaj

CHANGES

@@ -1,3 +1,11 @@
+2.0
+     * GPR#70: Switch to dune, opam v2
+     * GPR#60: Breaking change: switch from int codepoints to Uchar.t
+       codepoints
+     * GPR#59: Track lexing position
+
+-------------------------------------------------------------------------------
+
 1.99.4
      * GPR#47: Switch to ocaml-migrate-parsetree (contributed by Adrien Guatto)
      * GPR#42: Added 'Rep' (repeat operator) (contributed by jpathy)
@@ -16,7 +24,7 @@
      * First version of sedlex.  The history below refers to ulex, the ancestor
        or sedlex implemented with Camlp4.
 
---------------------------------------------------------------------------
+-------------------------------------------------------------------------------
 
 1.1
      * Generate (more) globally unique identifiers to avoid conflicts when open'ing another module

README.md

@@ -10,6 +10,9 @@ sedlex was originally written by Alain Frisch
 <[email protected]> and is now maintained as part of the
 ocaml-community repositories on github.
 
+## API
+The API is documented [here](https://ocaml-community.github.io/sedlex).
+
 ## Overview
 
 sedlex is a lexer generator for OCaml, similar to ocamllex, but

sedlex.opam

@@ -1,8 +1,15 @@
 opam-version: "2.0"
 name: "sedlex"
 synopsis: "An OCaml lexer generator for Unicode"
-version: "1.99.5"
+description: "
+sedlex is a lexer generator for OCaml. It is similar to ocamllex, but supports
+Unicode. Unlike ocamllex, sedlex allows lexer specifications within regular
+OCaml source files. Lexing specific constructs are provided via a ppx syntax
+extension.
+"
+version: "2.0"
 license: "MIT"
+doc: "https://ocaml-community.github.io/sedlex/index.html"
 maintainer: "Alain Frisch <[email protected]>"
 authors: [
   "Alain Frisch <[email protected]>"