- Added intro code blocks showing how to use find modules.
- Synced modules documentation.
- Extended few examples to make the intro code blocks fit into the
modules descriptions.
- Synced some RST formatting, variables descriptions and positions.
- Removed few redundant internal comments.
Issue: #26555
Since commit d74210a8bd (CMP0017: Remove support for OLD behavior,
2024-11-17) we can rely on CMP0017's NEW behavior unconditionally.
Calling `include(FindPackageHandleStandardArgs)` in a builtin module
will always get the builtin `FindPackageHandleStandardArgs`.
Alpine Linux has the `iconv.h` belonging to the builtin `iconv` library
provided by musl C library in the standard directory (`/usr/include`).
However, when installing the GNU libiconv APK package (`gnu-libiconv`),
the GNU `libiconv` library has header located in
`/usr/include/gnu-libiconv` subdirectory. Fix finding the header
matching the `libiconv` library.
Issue: #24695