Docs: instructions for use as external dependency

README.md

@@ -1,33 +1,60 @@
 # bazel_iwyu
-Bazel Support for IWYU. No Compilation Database needed.
+
+Bazel Support for IWYU. No Compilation Database needed. 
+Inspired by the [Bazel-Clang-Tidy](https://github.com/erenon/bazel_clang_tidy) project.
 
 ## How To Use
 
 1. Build and Install IWYU 0.18.0+ (Not needed for Linux x86_64 on `master`)
 
-2. Run IWYU
+2. In your WORKSPACE file, add
+
+```python
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
+http_archive(
+    name = "com_github_storypku_bazel_iwyu",
+    sha256 = "<sha-of-git-rev>",
+    strip_prefix = "bazel_iwyu-<git-rev>"
+    urls = [
+        "https://github.com/storypku/bazel_iwyu/archive/<git_rev>.tar.gz",
+    ],
+)
+
+load("@com_github_storypku_bazel_iwyu//bazel:dependencies.bzl", "bazel_iwyu_dependencies")
+bazel_iwyu_dependencies()
+```
+
+3. Add the following to your bazelrc. (E.g., `.bazelrc`)
+
+```
+build:iwyu --aspects @com_github_storypku_bazel_iwyu//bazel/iwyu:iwyu.bzl%iwyu_aspect
+build:iwyu --output_groups=report
 ```
+
+4. Run IWYU
+
+```shell
 bazel build --config=iwyu //path/to/pkg:target
 ```
 
-3. Apply fixes
+5. Apply fixes
 
 Suppose IWYU binaries/scripts can be found on PATH:
 
-```
+```shell
 fix_includes.py --nosafe_headers < bazel-bin/path/to/pkg/<target>.iwyu.txt
 ```
 
 for Linux-x86_64, You may find it convenient to have the top-level "external" symlink
 
-```
+```shell
 ln -s bazel-out/../../../external external
 ```
 
 And run
 
-```
+```shell
 external/iwyu_prebuilt_pkg/bin/fix_includes.py --nosafe_headers < bazel-bin/path/to/pkg/<target>.iwyu.txt
 ```
 
@@ -38,3 +65,7 @@ external/iwyu_prebuilt_pkg/bin/fix_includes.py --nosafe_headers < bazel-bin/path
 3. [ ] More IWYU mappings for other 3rd-party libraries, e.g., ABSL, Boost, Eigen, etc.
 4. [ ] Gather multiple X.iwyu.txt into one.
 5. [ ] Support for custom mapping files and IWYU options from users.
+
+## How to Contribute
+As with other OSS projects, suggestions and PRs are welcome!
+