refactor: rename project from remind_sync to ical2rem

- Rename executable public_name and package name from remind_sync to
  ical2rem
- Update dune-project with new name, source URI, maintainer, synopsis,
  description, and tags
- Add dune-build-info dependency and use Build_info to generate the
  version string at build time instead of the %%VERSION%% placeholder
- Add pinned dependencies to ical2rem.opam
- Remove remind_sync.opam
- Bump dune lang version from 3.20 to 3.23

bin/commandLine.ml

@@ -1,6 +1,11 @@
 open Cmdliner
 open Cmdliner.Term.Syntax
 
+let version_string () =
+  match Build_info.V1.version () with
+  | None -> "dev"
+  | Some v -> Build_info.V1.Version.to_string v
+
 let files =
   let doc = "Files to process" in
   Arg.(non_empty & pos_all string [] & info [] ~docv:"FILE" ~doc)
@@ -12,7 +17,7 @@ let timezone =
 let main_command f =
   let doc = "Convert iCalendar files to remind format" in
   let man = [] in
-  Cmd.make (Cmd.info "ical2rem" ~version:"%%VERSION%%" ~doc ~man)
+  Cmd.make (Cmd.info "ical2rem" ~version:(version_string ()) ~doc ~man)
   @@
   let+ files = files and+ tz = timezone in
   f tz files

bin/dune

@@ -1,10 +1,11 @@
 (executable
- (public_name remind_sync)
+ (public_name ical2rem)
  (name main)
  (modules main commandLine remind eventPredicates utils windows_tz)
  (preprocess
   (pps ppx_deriving.show))
  (libraries
+  dune-build-info
   cmdliner
   icalendar
   timedesc-tzdb.full