Rename DOCUMENTATION option to WITH_DOCS in CMakeLists.txt

[ssam18]

Problem

Fixes #3381

The CMakeLists.txt used DOCUMENTATION as the option name, while the README.md and config.mk consistently use WITH_DOCS. This naming inconsistency made it confusing for users who want to disable documentation building.

Current State

• CMakeLists.txt: Uses DOCUMENTATION option
• config.mk: Uses WITH_DOCS variable
• README.md: Documents make WITH_DOCS=no

Solution

Rename the CMake option from DOCUMENTATION to WITH_DOCS to match the Makefile convention and maintain consistency across the build system.

Changes

1. Renamed option(DOCUMENTATION ...) to option(WITH_DOCS ...)
2. Updated all references: if (DOCUMENTATION) → if (WITH_DOCS)
3. Maintains consistency with other CMake options (WITH_CLIENTS, WITH_BROKER, WITH_APPS, WITH_PLUGINS)

Usage

Before:

cmake -DDOCUMENTATION=OFF ..

After:

cmake -DWITH_DOCS=OFF ..

Backward Compatibility

This is a breaking change for users who explicitly set -DDOCUMENTATION=OFF in their CMake commands. However:

• The option was undocumented in README (which only mentions WITH_DOCS)
• It aligns with the established WITH_* naming convention
• Makes the build system more intuitive and consistent

Testing

• Verified the diff shows correct renaming
• Option maintains the same default value (ON)
• No functional changes to the build process

[SamareshSingh]

@jacmet @xrmx @onip @ncopa Please get a chance to review this small PR.