docs: update URL to tar file for boost-components documentation

[httpak]

• I've checked this Git style guide. [Yes]
• I've checked this CMake style guide. [Yes]
• My change will work with CMake 3.2 (minimum requirement for Hunter). [Yes]
• I will try to keep this pull request as small as possible and will try not to mix unrelated features. [Yes]
• My change will resolve this request: Boost path is broken - Quickstart doesn't work #546

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[NeroBurner]

Thanks for keeping the documentation up to date!

Could you make the title of this PR more descriptive? "Update tar" could be updating the tar package as well (at least that was my first thought)

How this this PR fix #546 as well? Please explain, as I don't quite understand.

[NeroBurner]

Released: https://github.com/cpp-pm/hunter/releases/tag/v0.26.0