Remove executable bit from 2 Markdown files

[rgoldberg]

Remove executable bit from 2 Markdown files.

Resolve #116

Checklist

• I've read the Contribution Guidelines
• My contributions are licensed under the Swift license.
• I've followed the coding style of the rest of the project.
• I've added tests covering all new code paths my change adds to the project (if appropriate).
• I've verified that my change does not break any existing tests.
• I've updated the documentation if necessary.

[rgoldberg]

@lorentey Hi. Sorry to contact out of the blue.

I assume that swift-atomics won't receive many (or possibly any) updates in the future given that Synchronization.Atomic is now available.

I, however, can't use that, because I cannot yet require my users to be running macOS 15+.

In the meantime, I must still use swift-atomics. I assume that others are in similar circumstances.

Could you possibly release a new version of swift-atomics that includes all of the post-1.2.0 improvements in main? One of them fixes a build warning that I keep encountering.

Thanks.

[rgoldberg]

@natecook1000 Sorry to bother you outside SAP, but do you know if anyone can release a new version of this library, swift-atomics? (I saw that you've contributed to this project)

Merging this PR wouldn't hurt (though it's completely inessential), but much more import is that main fixes build warnings that exist in the most recent released version of swift-atomics, and might have other fixes (I assume that no more work will be done for this project given that Synchronization.Atomic is now available, but my app can't use it since my app must support macOS older than 15).

Thanks for any help.

[lorentey]

Good catch, thanks!

[lorentey]

Yeah, 1.2.1 is long overdue for shipping. I'll see if I can quickly tag a release.