build: Improve version information and build process for `docman` package

- Include version information in the `docman` package
- Add version and build information to `ldflags` option in the `docman` package
- Update `vendorSha256` in the `docman` package

flake.nix

@@ -49,6 +49,7 @@
             # In 'nix develop', we don't need a copy of the source tree
             # in the Nix store.
             src = ././source;
+            version = "${version}";
 
             # This hash locks the dependencies of this package. It is
             # necessary because of how Go requires network access to resolve
@@ -64,8 +65,7 @@
             vendorSha256 = "sha256-81IBG8H1jsYKD+tmFeCpAWFdz6cuQDt9r+FV56xboBU=";
             
             ldflags = [
-                 "-X \"release.version=${version}\""
-                 "-X \"release.build=${build}\""
+                 "-X 'release.version=${version}' -X 'release.build=${build}'"
                       ];
                       
             buildInputs = [ versionTool.defaultPackage.${system} ];