[vcpkg-cmake] Fix docs and usage of option MAYBE_UNUSED_VARIABLES (#19245)

* Remove unused cmake options and MAYBE_UNUSED_VARIABLES values

* Update MAYBE_UNUSED_VARIABLES docs

* update version

* version stuff

* version stuff

* update docs

2 files changed, 24 insertions, 3 deletions

diff --git a/docs/maintainers/ports/vcpkg-cmake/vcpkg_cmake_configure.md b/docs/maintainers/ports/vcpkg-cmake/vcpkg_cmake_configure.md
index 3745df080..6053b363c 100644
--- a/docs/maintainers/ports/vcpkg-cmake/vcpkg_cmake_configure.md
+++ b/docs/maintainers/ports/vcpkg-cmake/vcpkg_cmake_configure.md
@@ -19,7 +19,7 @@ vcpkg_cmake_configure(
     [OPTIONS_DEBUG
         <configure-setting>...]
     [MAYBE_UNUSED_VARIABLES
-        <variable-name>...]
+        <option-name>...]
 )
 ```
 
@@ -61,7 +61,17 @@ If the library sets its own code page, pass the `NO_CHARSET_FLAG` option.
 This function makes certain that all options passed in are used by the
 underlying CMake build system. If there are options that might be unused,
 perhaps on certain platforms, pass those variable names to
-`MAYBE_UNUSED_VARIABLES`.
+`MAYBE_UNUSED_VARIABLES`. For example:
+```cmake
+vcpkg_cmake_configure(
+    ...
+    OPTIONS
+        -DBUILD_EXAMPLE=OFF
+    ...
+    MAYBE_UNUSED_VARIABLES
+        BUILD_EXAMPLE
+)
+```
 
 `LOGFILE_BASE` is used to set the base of the logfile names;
 by default, this is `config`, and thus the logfiles end up being something like
diff --git a/docs/maintainers/vcpkg_configure_cmake.md b/docs/maintainers/vcpkg_configure_cmake.md
index fd6ce1318..8a1eb3284 100644
--- a/docs/maintainers/vcpkg_configure_cmake.md
+++ b/docs/maintainers/vcpkg_configure_cmake.md
@@ -17,7 +17,7 @@ vcpkg_configure_cmake(
     [OPTIONS <-DUSE_THIS_IN_ALL_BUILDS=1>...]
     [OPTIONS_RELEASE <-DOPTIMIZE=1>...]
     [OPTIONS_DEBUG <-DDEBUGGABLE=1>...]
-    [MAYBE_UNUSED_VARIABLES <option-name>...]
+    [MAYBE_UNUSED_VARIABLES <OPTION_NAME>...]
 )
 ```
 
@@ -58,6 +58,17 @@ Additional options passed to CMake during the Debug configuration. These are in
 
 ### MAYBE_UNUSED_VARIABLES
 Any CMake variables which are explicitly passed in, but which may not be used on all platforms.
+For example:
+```cmake
+vcpkg_cmake_configure(
+    ...
+    OPTIONS
+        -DBUILD_EXAMPLE=OFF
+    ...
+    MAYBE_UNUSED_VARIABLES
+        BUILD_EXAMPLE
+)
+```
 
 ### LOGNAME
 Name of the log to write the output of the configure call to.