Change README links to be doxygen-friendly

[dstebila]

Fixes #1897.

• [No] Does this PR change the input/output behaviour of a cryptographic algorithm (i.e., does it change known answer test values)? (If so, a version bump will be required from x.y.z to x.(y+1).0.)
• [No] Does this PR change the list of algorithms available -- either adding, removing, or renaming? Does this PR otherwise change an API? (If so, PRs in fully supported downstream projects dependent on these, i.e., oqs-provider will also need to be ready for review and merge by the time this is merged.)

[dstebila]

It seems that Doxygen has strong opinions about upper/lowercase on anchors generated from Markdown, and these opinions differ from Github's choices. In my tests the links still scroll to the right anchors in the cross-referenced page, but someone else please confirm. It would be annoying to break cross-references in one program to make them work in another program, and vice versa.

[mouse07410]

I'm inclined to say: while this PR is not perfect, it unbreaks building of docs. Thus, let us merge it, and add improvements later. Rather than argue about the best way, while gen_docs remains broken/unusable.

[dstebila]

Do we want to merge this now for inclusion in 0.11.0? I can't think of a risk that would merit a new release candidate, but want to check if anyone has another opinion.

[SWilson4]

Do we want to merge this now for inclusion in 0.11.0? I can't think of a risk that would merit a new release candidate, but want to check if anyone has another opinion.

I can't imagine any risk in including this, and it would be nice to have working release docs on macOS.

[SWilson4]

I will go ahead and hit merge, as there seems to be consensus (based on approvals/thumbs-ups) that (1) this is desirable for the release and (2) it's not necessary to cut a new RC.

[dstebila]

Thanks Spencer!