Update formatting library.

vendor/Fmt/support/bazel/README.md

@@ -0,0 +1,73 @@
+# Bazel support
+
+To get [Bazel](https://bazel.build/) working with {fmt} you can copy the files `BUILD.bazel`, `WORKSPACE.bazel`, `.bazelrc`, and `.bazelversion` from this folder (`support/bazel`) to the root folder of this project. This way {fmt} gets bazelized and can be used with Bazel (e.g. doing a `bazel build //...` on {fmt}). 
+
+## Using {fmt} as a dependency
+
+The following minimal example shows how to use {fmt} as a dependency within a Bazel project.
+
+The following file structure is assumed:
+
+```
+example
+├── BUILD.bazel
+├── main.cpp
+└── WORKSPACE.bazel
+```
+
+*main.cpp*:
+
+```c++
+#include "fmt/core.h"
+
+int main() {
+  fmt::print("The answer is {}\n", 42);
+}
+```
+
+The expected output of this example is `The answer is 42`.
+
+*WORKSPACE.bazel*:
+
+```python
+load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+
+git_repository(
+    name = "fmt",
+    branch = "master",
+    remote = "https://github.com/fmtlib/fmt",
+    patch_cmds = [
+        "mv support/bazel/.bazelrc .bazelrc",
+        "mv support/bazel/.bazelversion .bazelversion",
+        "mv support/bazel/BUILD.bazel BUILD.bazel",
+        "mv support/bazel/WORKSPACE.bazel WORKSPACE.bazel",
+    ],
+    # Windows-related patch commands are only needed in the case MSYS2 is not installed.
+    # More details about the installation process of MSYS2 on Windows systems can be found here:
+    # https://docs.bazel.build/versions/main/install-windows.html#installing-compilers-and-language-runtimes
+    # Even if MSYS2 is installed the Windows related patch commands can still be used.
+    patch_cmds_win = [
+        "Move-Item -Path support/bazel/.bazelrc -Destination .bazelrc",
+        "Move-Item -Path support/bazel/.bazelversion -Destination .bazelversion",
+        "Move-Item -Path support/bazel/BUILD.bazel -Destination BUILD.bazel",
+        "Move-Item -Path support/bazel/WORKSPACE.bazel -Destination WORKSPACE.bazel",
+    ],
+)
+```
+
+In the *WORKSPACE* file, the {fmt} GitHub repository is fetched. Using the attribute `patch_cmds` the  files `BUILD.bazel`, `WORKSPACE.bazel`, `.bazelrc`, and `.bazelversion` are moved to the root of the {fmt} repository. This way the {fmt} repository is recognized as a bazelized workspace. 
+
+*BUILD.bazel*:
+
+```python
+cc_binary(
+    name = "Demo",
+    srcs = ["main.cpp"],
+    deps = ["@fmt"],
+)
+```
+
+The *BUILD* file defines a binary named `Demo` that has a dependency to {fmt}.
+
+To execute the binary you can run `bazel run //:Demo`.
+