user can deps nlohmann json using bazel directly

BUILD.bazel

@@ -0,0 +1,13 @@
+licenses(["notice"])  # 3-Clause BSD
+
+exports_files(["LICENSE.MIT"])
+
+cc_library(
+    name = "json",
+    hdrs = glob([
+        "include/**/*.hpp",
+    ]),
+    includes = ["include"],
+    visibility = ["//visibility:public"],
+    alwayslink = 1,
+)

WORKSPACE

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+workspace(name = "nlohmann_json")