docs: Refactor code structure for improved readability

bun/BUILD.bazel

@@ -5,6 +5,9 @@ load(":version.bzl", "BUN_VERSION")
 exports_files([
     "defs.bzl",
     "extensions.bzl",
+    "repositories.bzl",
+    "toolchain.bzl",
+    "version.bzl",
 ])
 
 bzl_library(
@@ -13,6 +16,19 @@ bzl_library(
     visibility = ["//visibility:public"],
 )
 
+bzl_library(
+    name = "extensions_bzl",
+    srcs = ["extensions.bzl"],
+    visibility = ["//visibility:public"],
+    deps = ["//internal:bun_install_bzl"],
+)
+
+bzl_library(
+    name = "repositories_bzl",
+    srcs = ["repositories.bzl"],
+    visibility = ["//visibility:public"],
+)
+
 bzl_library(
     name = "defs_bzl",
     srcs = ["defs.bzl"],