Add a page about mingw-w64 wildcard expansion

We want to change the default, so add some docs we can point
to in the upcoming NEWS entry.

mkdocs.yml

@@ -118,6 +118,7 @@ nav:
           - docs/autotools.md
           - docs/python.md
           - docs/git.md
+          - docs/c.md
           - docs/cpp.md
           - docs/pkgconfig.md
           - docs/pacman.md

web/docs/c.md

@@ -0,0 +1,32 @@
+# C/C++
+
+## Expanding wildcard arguments
+
+For making your program accept wildcard arguments, the official MSVC way is to
+link [w]setargv.obj to your program. By default it is not enabled. For more
+details see
+https://learn.microsoft.com/en-us/cpp/c-language/expanding-wildcard-arguments
+
+With mingw-w64 there are three ways wildcard expansion con be configured:
+
+1. mingw-w64 can be configured at build time to either enable or disable wildcard expansion by default via the `--enable-wildcard` configure flags. This can to be overridden on a per .exe basis by the user.
+
+    Currently wildcard expansion is enabled by default in MSYS2.
+
+2. You can set `_dowildcard` in your source code to either `0` or `-1` to disable or enable wildcard expansion.
+
+    ```c
+    // To force-enable wildcard expansion
+    int _dowildcard = -1;
+    // To force-disable wildcard expansion
+    int _dowildcard = 0;
+    ```
+
+3. You can link in `CRT_noglob.o` or `CRT_noglob.o` to disable or enable wildcard expansion. This will error out if `_dowildcard` is already set in the source.
+
+    ```bash
+    # To enable force-enable wildcard expansion
+    gcc main.c $(clang -print-file-name=CRT_glob.o)
+    # To force-disable wildcard expansion
+    gcc main.c $(clang -print-file-name=CRT_noglob.o)
+    ```