[docs] Add comment about VCPKG_TARGET_TRIPLET to README and installing package

[SallySoul]

Describe the pull request

• What does your PR fix?

I recently had an issue where I needed to specify VCPKG_TARGET_TRIPLET. I now see that I missed the critical piece of information at the bottom of integration.md. However, I'm of the opinion. VCPKG_TARGET_TRIPLET deserved some mention in a couple other areas.

• Which triplets are supported/not supported? Have you updated the [CI baseline]

Its a documentation update.

• Does your PR follow the [maintainer guide]

To the best of my knowledge

• If you have added/updated a port: Have you run ./vcpkg x-add-version --all and committed the result?

N/A

[ghost]

All CLA requirements met.

[PhoebeHui]

@SallySoul, thanks for the PR! Could you sign the CLA?

[SallySoul]

Signed. I can't re-run the checks though.

[PhoebeHui]

The baseline issue would be fixed by PR #19633. I will rerun the CI after the PR merged.

[strega-nil-ms]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Neumann-A]

also needs info about VCPKG_HOST_TRIPLET to be complete

[SallySoul]

@Neumann-A sure, I'll update the PR shortly.

[SallySoul]

@PhoebeHui Is there anything needed from me to push this along?

[PhoebeHui]

@SallySoul, It looks good for me now, thanks!

[BillyONeal]

I'm not entirely convinced that this warrants such a big block in the front "readme" -- since the longer readmes get the less likely people are to actually read them, and we don't expect most customers to need to customize triplets that often. If it is something that should be in the readme, I made some changes I would prefer to see against this: BillyONeal@d17fdc0

I want @strega-nil / @strega-nil-ms to take a look before landing this since she has Strong opinions about our docs.

[strega-nil-ms]

I'm of the opinion that triplets are important enough that they belong in the README, or at least in the first thing people read; however, it doesn't make sense to me to put it under the CMake integration section. Maybe it's own section?

[BillyONeal]

The maintainers talked about this in person today and we are OK with adding a block about triplets into the readme but would like @SallySoul to address Nicole's (@strega-nil / @strega-nil-ms ) concerns before merging this.

[SallySoul]

@strega-nil Happy to make changes. However, I need some clarification.

First, my experience with vcpkg is limited to use with cmake projects. What are some other use cases of vcpkg targets that I should be mindful of?

Also, where would you like this new section in the README? Given that cmake has a relatively large block in the the current structure, it's not clear to me where a triplet section would belong. Maybe right after the cmake section under "Getting Started"?

[strega-nil-ms]

@SallySoul I honestly think that yeah, it could just be its own section. Adding a blurb about how to use this from msbuild would be good too, but I can write that blurb.

[PhoebeHui]

Ping @SallySoul for response.

[PhoebeHui]

We don't have permission to push changes to this PR, closing this PR since it seems that no progress is being made. Please reopen if work is still being done.