chore: add type for options param into Timestamp.jsonStringify

lib/date/build.zig

@@ -32,4 +32,10 @@ pub fn build(b: *std.Build) void {
         .optimize = optimize,
     });
     lib_mod.addImport("zeit", dep_zeit.module("zeit"));
+
+    const dep_json = b.dependency("json", .{
+        .target = target,
+        .optimize = optimize,
+    });
+    lib_mod.addImport("json", dep_json.module("json"));
 }

lib/date/build.zig.zon

@@ -8,6 +8,9 @@
             .url = "git+https://github.com/rockorager/zeit#fb6557ad4bd0cd0f0f728ae978061d7fe992c528",
             .hash = "zeit-0.6.0-5I6bk29nAgDhK6AVMtXMWhkKTYgUncrWjnlI_8X9DPSd",
         },
+        .json = .{
+            .path = "../json",
+        },
     },
     .paths = .{
         "build.zig",

lib/date/src/timestamp.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const zeit = @import("zeit");
+const json = @import("json");
 
 pub const DateFormat = enum {
     rfc1123,
@@ -9,7 +10,7 @@ pub const DateFormat = enum {
 pub const Timestamp = enum(zeit.Nanoseconds) {
     _,
 
-    pub fn jsonStringify(value: Timestamp, options: anytype, out_stream: anytype) !void {
+    pub fn jsonStringify(value: Timestamp, options: json.StringifyOptions, out_stream: anytype) !void {
         _ = options;
 
         const instant = try zeit.instant(.{