more intuitive portable-atomic feature etc.

[brody4hire]

Fixes #170 - non-breaking feature update - based on & supersedes PR #171

UPDATED as follows

• include dep: syntax updates from PR Use dep: syntax for portable-atomic #171
• update some documentation to update reference & avoid duplicated info
• increase MSRV to 1.60 in Cargo.toml & in .github/
• crate version -> 0.10.0

I have also tried CI in my own fork: brody4hire#1

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P.S. I was hoping that the implicit feature support would be removed in Rust 2024, which is part of the root cause, but this update is now held up: rust-lang/cargo#12826 (comment)

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/cc @jamesmunns @Dirbaio

[zesterer]

Any chance you could bump the MSRV too? You can find it in .github/

[brody4hire]

I have now rebased this PR on PR #171, updated some documentation to avoid duplicated info, updated MSRV in both Cargo.toml & .github/, etc. I have also updated the crate version in its own commit in case this may be helpful.

Please let me know if anything else is needed from me, my apologies for the delay.

/cc @jamesmunns @Dirbaio

[brody4hire]

Now updated again, as discussed, tested in my personal fork: brody4hire#1

Please let me know if anything else is needed from me.