Improve Windows build instruction (#1079)

PiperOrigin-RevId: 686026277

Author: tats-u

docs/build_mozc_in_windows.md

@@ -24,6 +24,8 @@ out_win\Release\Mozc64.msi
 
 Hint: You can also download `Mozc64.msi` from GitHub Actions. Check [Build with GitHub Actions](#build-with-github-actions) for details.
 
+Hint: You can use Bazel to build Mozc (experimental). For details, please see below.
+
 ## Setup
 
 ### System Requirements
@@ -41,6 +43,8 @@ Building Mozc on Windows requires the following software.
     * `requests`
   * `.NET 6` or later (for `dotnet` command).
 
+For additional requirements for building Mozc with Bazel, please see below.
+
 ### Install pip modules
 
 ```
@@ -160,12 +164,26 @@ Note that you can specify `--qtdir=` option instead of `--noqt` in GYP phase sin
 
 ## Build with Bazel (experimental)
 
+Additional requirements:
+
+* [Bazel](https://bazel.build/)
+* [MSYS2](https://github.com/msys2/msys2)
+
+After running `build_tools/update_deps.py` and `build_tools/build_qt.py`, run the following command instead of `build_mozc.py`:
+
 ```
 bazel --bazelrc=windows.bazelrc build --config oss_windows --config release_build package
 ```
 
 You have release build binaries in `bazel-bin\win32\installer\Mozc64.msi`.
 
+### Tips for Bazel setup
+
+* You do not need to install a new JDK just for Mozc.
+* If you installed Bazel via [Scoop](https://scoop.sh), it is recommended to install MSYS2 via Scoop, too.
+
+https://bazel.build/install/windows?hl=ja#install-compilers
+
 ---
 
 ## Build with GitHub Actions