[bazel][docs] Mention how to provide path to compiler

[aeubanks]

Summary

And some other cleanups/clarifications.

utils/bazel/README.md

 
 1. `git clone https://github.com/llvm/llvm-project.git; cd llvm-project` if
    you don't have a checkout yet.
 2. Install Bazel at the version indicated by [.bazelversion](./.bazelversion),
    following the official instructions, if you don't have it installed yet:
    https://docs.bazel.build/versions/main/install.html.
 3. `cd utils/bazel`
 4. `bazel build --config=generic_clang @llvm-project//...` (if building on Unix
-   with Clang). `--config=generic_gcc` and `--config=msvc` are also available.
+   with Clang/LLD). `--config=generic_gcc` and `--config=msvc` are also
+   available.
 
 
 # Configuration
 
 The repository `.bazelrc` will import user-specific settings from a
 `user.bazelrc` file (in addition to the standard locations). Adding your typical
 config setting is recommended.
 
 ```.bazelrc
 build --config=generic_clang
 ```
 
 You can enable
 [disk caching](https://docs.bazel.build/versions/main/remote-caching.html#disk-cache),
 which will cache build results
 
 ```.bazelrc
 build --disk_cache=~/.cache/bazel-disk-cache
 ```
 
 You can instruct Bazel to use a ramdisk for its sandboxing operations via
 [--sandbox_base](https://docs.bazel.build/versions/main/command-line-reference.html#flag--sandbox_base),
-which can help avoid IO bottlenecks for the symlink stragegy used for
+which can help avoid IO bottlenecks for the symlink strategy used for
 sandboxing. This is especially important with many inputs and many cores (see
 https://github.com/bazelbuild/bazel/issues/11868):
 
 ```.bazelrc
 build --sandbox_base=/dev/shm
 ```
 
 Bear in mind that this requires that your ramdisk is of sufficient size to hold
 any temporary files. Anecdotally, 1GB should be sufficient.
 
+To specify a specific local compiler to use, add the following bazel flag:
+
+```.bazelrc
+build --repo_env=CC=$PATH_TO_CC
+```
+
 # Coverage
 
 The LLVM, MLIR, and Clang subprojects have configurations for Linux (Clang and
 GCC), Mac (Clang and GCC), and Windows (MSVC). Configuration options that are
 platform-specific are selected for in defines. Many are also hardcoded to the
 values currently used by all supported configurations. If there is a
 configuration you'd like to use that isn't supported, please send a patch.